Medication injector apparatus with drive assembly that facilitates reset

IS 2 365 807 T3

DESCRIPTION

Medication injector device with motor assembly that facilitates resetting

Background of the invention

The present invention relates to an injection device assembly that when actuated emits a click for a medication injector apparatus such as injection pens.

Patients suffering from various diseases, such as diabetes, must frequently inject themselves with medication, such as insulin solutions. To enable a person to conveniently and accurately self-administer appropriate doses of medicament, various devices known widely as injector pens or injection pens have been developed.

To allow a person to administer an appropriate dose, injection pens have been equipped with a wide variety of dosing and injection mechanisms that allow a particular dosage to be conveniently selected and then dispensed. Generally, these pens are equipped with a cartridge that includes a plunger and that contains a multi-dose amount of liquid medication. A drive member can be moved forward to advance the plunger in the cartridge such that it dispenses the contained medication from the opposite end of the cartridge, typically through a needle that penetrates a plug at that opposite end. In reusable pens, once the pen has been used to the end of the supply of medication within the cartridge, a user can remove and dispose of the spent cartridge. Then, to prepare for the next cartridge, the drive member that attaches to the pen cartridge is reset to its initial position, manually or automatically during attachment of a replacement cartridge, and the injection pen can be used as continued until that next cartridge is shaken.

EP 0 937 471 describes a medication delivery pen comprising a dose control mechanism, a drive mechanism to dispense the desired dose and a barrel stem tube to interface between the dose control mechanism. with the drive.

In order to allow the re-usable injection pen plunger drive member to be reset, various assemblies have been used. One known assembly uses a nut fixed within the housing, such as by ultrasonic welding, which nut is threadedly attached to a drive screw which when rotated can extend from the base of the injection pen to advance the plunger of a cartridge within. of a retention element mounted on the base of the boom. Rotation of the drive screw to screw through the nut set to advance the plunger is done by a toothed drive clutch, keyed to rotate with the screw, which engages a toothed drive member that rotates during operation of the injection mechanism. . The drive clutch, which is biased into a torque transmission relationship with the drive member when the cartridge retainer is mounted on the base of the boom, is biased away from the toothed drive member when the cartridge retainer member cartridge is removed. Although effective in advancing the drive screw, and in allowing the screw to reset or be pushed back to the base of the pen during the cartridge retainer assembly process, this assembly is not without its disadvantages. For example, due to the relatively large size of the drive clutch, a flywheel effect of the rotating clutch during screw reset may cause the screw to retract so much that initial boom loading may be inconvenient.

The injection pens have been equipped with an assortment of mechanisms that generate audible clicking noise during the injection process. This one-click noise is intended to inform a user that the pen is working to deliver medication. A known pen uses a click-actuated injection device mechanism employing a series of radially extending leaf springs arranged around the periphery of a disc-shaped portion, projecting radially from a drive sleeve. injection mechanism. As the pen injection mechanism is actuated, the drive sleeve rotates, causing the rotation of a clutch that has been moved axially during assembly of the pen to engage by teeth that extend axially in the distal direction from the radially projecting portion of the drive sleeve. As the clutch rotates, a drive screw that extends through the drive sleeve and to which the clutch is keyed is turned, and the drive screw advances axially as it is screwed through a nut within the housing. of the pen to move a cartridge plunger and eject medicine from the pen. During rotation of the driver sleeve, radially extending leaf springs arranged around the radially projecting portion of the driver sleeve slide into and out of recesses in the pen housing located radially outward therefrom, thereby producing audible clicking noises associated with the injection. Leaf springs, when inserted into the housing bores after the drive sleeve rotation has stopped, are designed to prevent counter-rotation of the drive sleeve that would allow undesirable backing of the drive screw. Although useful, this clickable injection device design is not without its drawbacks. For example, modifying the feel and sound of injection clicks during pen design may involve modifications to the cavities of the housing mold. Furthermore, leaf springs that extend

ES 2 365 807 T3 radially can undesirably increase the overall contour of the injection pen.

In another injection pen described in US Patent No. 5,688,251, an injection device is provided which when actuated clicks by a distal clutch biased by a spring with axially oriented teeth that is coaxially disposed over and grooved. for a nut that mates with a guide screw that can be advanced. The spring that biases the distal clutch teeth against the housing plug to create an audible click during injection also biases a proximal clutch against a pusher to create audible feedback during dose selection. Although perhaps functional, this design is not without its drawbacks. For example, since the spring used within the audible injection feedback design is also used as part of the select audible feedback design, the audible injection feedback cannot be tuned or adjusted by modifying that spring without also affecting the audible feedback. pick, and possibly other characteristics such as pick torque.

Another limitation of reusable injection pens is that, because different types of medications, provided in different cartridges, may possibly be used with the same reusable pen body, it is necessary for a user of the injection pen and those various cartridges to be vigilant to ensure that the pen is used to deliver the correct dosage of medicine. To assist a user in identifying the drug contained in a cartridge, a cartridge recognition system has been previously described in US Patent No. 5,954,700. In that system, a drug filled cartridge includes an information source designed to provide information regarding the cartridge to the electronic delivery device, such as an injection pen for which it is adapted. Although useful, the information provided does not necessarily result in the delivery device indicating to a user the actual dose of medication being delivered by the delivery device, and miscalculations on the part of the user are possible, resulting in doses. incorrect.

Another limitation of some injection pens relates to the dose setting mechanism. A mechanism described in US Patent No. 5,509,905 includes switches that are used in signal formation when the switches are actuated during a user's rotation of an operating head extending from the base of the boom. . The signals are used to mathematically establish the number of unit volumes set by the user. However, the use of cams to actuate the switches results in the resistance to rotation of the operating head varying perceptibly during rotation of that operating head.

Another problem with some existing injection pens is that the dosing and injection operations of the pen are not intuitive for all users. In particular, with some pens, the user must first rotate a knob on the pen to set the dose of medicine to be administered as indicated by the numbers on a marked selector permanently connected to the knob, and then apply a force axial or thrust by means of a plunger that moves the control axially to inject the dose of medicine. Since for some pen designs, the knob and selector will have undergone translation axially out of the pen base, while being rotated during dose setting, and also since the knob and selector, when pushed by plunger during injection, they also rotate back towards the base of the pen to provide, through their markings, a continuous indication of the amount of medicine remaining to be administered, a user may come to believe that turning the proximally extending knob downward will inject medication. However, such a belief is erroneous for at least one pen design, and therefore a user operating under such an erroneous belief may not properly self-administer the desired medication.

In a well known disposable injection pen design, a dose is set in a similar manner by turning out a knob, connected to a dial marked with numbers, so that the dial is translated outward as it rotates. As the dial is rotated, a sequence of numbers arranged helically on the dial is visible through a viewing window to show the dose that has been set for the pen to deliver. In this design, the application of a plunger thrust force moves the knob and selector axially and without rotation to inject the drug dose. However, while useful, this design is not without its downsides. First, during plunger push, few, if any, of the numbers that indicate the dose that have been passed are displayed when adjusting the pen, which can be a source of confusion for some users. Also, once the pen has been used for injection, the dial has to be reset before it can be screwed out to set the next dose to be administered. Resetting requires a rotation of the selector to a zero position, except for a limited number of previously injected dose quantities, followed by an axial movement of the selector.

Therefore, it would be desirable to provide a device or method that overcomes one or more of these and other disadvantages of the prior art.

IS 2 365 807 T3

Brief summary of the invention

In accordance with the present invention, there is provided an injection device assembly which upon actuation emits a click of claim 1.

Preferred aspects of the present invention are set forth in the appended claims.

An advantage of the present invention is that an injection device assembly can be provided which when actuated emits a click that generates an audible indication to a user of the injection operation of the portable injector in which it is installed.

Another advantage of the present invention is that an injection device assembly can be provided which when actuated emits a click that is easily tunable during manufacturing design, such as altering a constant or preload of a spring of a pusher element, to provide the desired pitch and volume of the audible injection feedback.

Yet another advantage of the present invention is that an injection device assembly can be provided which when actuated emits a click that can be tuned during manufacture independent of any audible selection feedback or selection torque from a pen it is on. installed.

Yet another advantage of the present invention is that an injection device assembly can be provided which, when actuated, emits a click that can be designed to serve as a non-return mechanism for a forward drive screw.

Yet another advantage of the present invention is that an injection device assembly can be provided which when actuated clicks that is structured and arranged to utilize space effectively so as not to adversely affect the length or contour of the pen. in which it is installed.

Brief description of the drawings

Embodiments of apparatus according to the present invention will now be described, by way of example only, with reference to the accompanying drawings. In the drawings, as precisely illustrated, only the apparatus of Figures 8-11 and 23-30 are in accordance with the present invention. In the drawings:

Figure 1 is a schematic plan view of a drug injection pen capable of being equipped with a dose injection mechanism that includes the clickable injection device assembly of the present invention;

Figure 2 is a partial cross-sectional plan view showing schematically the injection pen of Figure 1 prior to mounting of the cartridge assembly to the base of the reusable pen, and with the drive screw of the drive assembly projecting from the end distal of the base of the pen;

Figure 3 is a fragmentary plan view in cross section schematically showing the base of the reusable pen of Figure 2;

Figure 4 is a fragmentary plan view in cross section showing schematically the injection pen of Figure 1 with the cartridge assembly fully assembled to the base of the reusable pen;

Figure 5 is a perspective view of the power unit, and a rotating power member that drives the operation of the power unit, removed from the injection pen of Figure 1;

Figure 6 is an exploded cross-sectional view of an injection nut and drive clutch of a drive assembly;

Figure 7 is a fragmentary cross-sectional plan view schematically showing another injection pen in which a drive assembly pushes a cartridge forward into a retainer mountable at the base of the pen;

Fig. 8 is a fragmentary cross-sectional view schematically showing parts of an injection pen equipped with one form of a click injection device assembly of the present invention;

Figure 9 is a fragmentary cross-sectional view schematically showing another form of an injection device assembly that when actuated clicks into parts of another injection pen;

Figure 10 is an exploded perspective view of the injection device assembly that when actuated emits a click of Figure 9 and the parts of the injection mechanism with which it interacts;

Figure 11 is an opposite perspective view of Figure 10;

Figure 12 is a block diagram representation of one form of therapeutic dose indicating apparatus;

Figure 13 is a schematic plan view of an injection pen as a delivery device, equipped with one form of the therapeutic dose indicating apparatus shown in Figure 12;

IS 2 365 807 T3

Figure 14 is a cross-sectional view of a cartridge assembly removed from the injection pen of Figure 13;

Figure 15 is a plan view of a first arrangement of a barrel shaft of the cartridge assembly of Figure 14;

Figure 16 is a plan view of a second arrangement of a barrel shaft of the cartridge assembly of Figure 14;

Figure 17 is a plan view of a third arrangement of a barrel shaft of the cartridge assembly of Figure 14;

Figure 18 is a schematic representation of how one form of therapeutic dose indicating apparatus works;

Figure 19 is a schematic plan view in partial cross-section of an array of sensors and a rotating die mounted on the selector in a form of a dosable quantity identifier;

Figure 20 is a plan view of the rotary die of Figure 19 shown unrolled and removed from the dose setting selector;

Figure 21 is a plan view of the array of sensors removed from the array mounted on the selector of Figure 19, in which the sensor contacts are shown in dashed lines;

Figure 22 is a plan view of another arrangement of a dosable quantity identifier of the present invention;

Fig. 23 is a top view of one form of an injection pen equipped with an assembly for selectively rotating a driver sleeve to inject a set dose with an injection device assembly embodiment that clicks upon actuation;

Figure 24 is a front cross-sectional view of the injection pen of Figure 23 prior to manually rotating the dose setting knob to set the dose to be delivered by further operation of the injection pen;

Figure 25 is a cross-sectional view conceptually similar to the view of Figure 24 once the cap has been removed, the pen is in a primed state, and the dose setting knob has been rotated to set the dose. dosage for administration;

Figure 26 is a cross-sectional view conceptually similar to the view of Figure 25 after the dose setting knob has been pushed slightly for mechanical transition of the pen to a dose injection state;

Figure 27 is an exploded rear perspective view of the injection pen of Figure 23;

Figure 28 is a front perspective view of the slide guide assembly of Figure 27;

Figure 29 is another rear perspective view of the contact assemblies of Figure 27; Y

Figure 30 is a plan view of the rotary die of Figure 27 shown unrolled and removed from the remainder of the injection pen.

Corresponding reference characters indicate corresponding parts throughout the various views. Although the drawings depict embodiments of the present invention, the drawings are not necessarily to scale, and some features may be exaggerated or omitted from some of the drawings to better illustrate and explain the present invention.

Detailed description of the invention

Figure 1 generally illustrates one type of medication delivery device in which the clickable injection device assembly of the present invention finds beneficial application. The delivery device shown is a reusable medication injection pen, generally designated 20. As is generally known in reusable devices of this type, injection pen 20 includes a medication-filled cartridge 22 as part of a cartridge assembly, generally designated 24, that is connected to a base of the reusable pen, designated usually like 26. The pen base 26 preferably includes dose setting and injection mechanisms that operate to allow an amount of the medication to be selected and then expelled from the cartridge assembly 24 through the injection needle assembly 27 which is sample attached to it. In the device shown, an exposed knob 28 with rotary knob 30 thereon, at the proximal or posterior end of the pen base 26 is a manually operable part of the dose setting and injection mechanisms, otherwise housed within the boom base 26. During the dose setting process, knob 28 is designed to be able to rotate to set the dose, and when knob 28 is rotated in this manner to increase the selected dose, knob 28 and knob 30 move out of range. the base of boom 26 from the axial position shown in Figure 1, or to the right from an observer's perspective of Figure 1. During the dose injection process that occurs after the dose setting process, when a plunger push force is applied to knob 30, which rotates freely relative to knob 28, knob 30 and knob 28 are designed to move to the left and back to the axial position shown in figure 1, to cause the components of the injection mechanism housed within the base of the pen to operate to cause the medication to be injected into the cartridge.

IS 2 365 807 T3

The foregoing is provided as background and is intended to be illustrative and not limiting at all, as various injectors are known in the injection pen art, having various manual dose setting and injection mechanisms, and having various forms. and external sizes. The powertrain can be easily adapted to many of these mechanisms in view of the explanation in this document, since the powertrain described further below in theory can be incorporated into any type of injection mechanism that during injection rotates a motive element. rotary that introduces a rotational force into the drive assembly. Additionally, the drive assembly can be applied to autoinjectors that have rotating drive elements, and also do not require the presence of a dose setting mechanism that allows variability in the amount to be administered.

Referring further to Figure 2, in which the needle assembly is not shown attached thereto, the cartridge assembly 24 is assembled from the component parts during its production in a user-operated unit as a single piece. , and is disposed of as a unit when the contained drug is spent. Cartridge 22 of cartridge assembly 24 includes an open-ended glass housing 32 that defines an internal volume filled with medication, such as human growth hormone or insulin. A slide plunger 34 engages the inner surface 33 of the cartridge housing in a fluid-tight manner. A rod tip 35 used to distribute the forward forces applied to plunger 34, and which is freely movable within the internal volume of the cartridge located proximal to plunger 34, has a base disc 37 formed in one piece with a cylindrical collar 38 into which the distal end 121 of the driver screw 120 of the driver assembly of the invention fits. If rod tip 35 is removed, distal end 121 of drive screw 120 can be directly, as opposed to indirectly, coupled to plunger 34. Alternatively, when the pen is to be used with cartridges lacking a rod tip, it can be mounted so that a base piece that is larger in diameter than the drive screw can rotate and is designed to rotate relative to the drive screw in distal end 121 to be directly coupled to the cartridge plunger.

Cartridge 22 is further protected by an outer casing 42, which is shown to be transparent, but which can be constructed otherwise. At its rear end, the outer casing 42 includes an externally threaded, reduced neck portion 44, and a further reduced rear axle 46 into which the rear end of the rod tip 35 extends. The threaded neck portion 44 allows for a threaded or screw connection of cartridge assembly 24 to pen base 26. Cartridge assembly 24 includes plug 50 that is attached during production, such as by ultrasonic welding, to outer shell 42 to capture cartridge 22 within the outer shell. A pierceable rubber septum 54 is pressed by plug 50 against cartridge housing 32 to seal the open front end of the housing. External threads on plug 50 allow mounting of injection needle assembly 27. When assembly 27 is assembled in this manner, the rear end of its needle pierces septum 54, and medication is ejected from cartridge 22 through the needle when plunger 34 is pushed to the left in Figure 1 during use. injection pen 20.

The cartridge assembly that is actuated by the power assembly of the present invention may be configured differently, as is known in the art. For example, and as further shown in Figure 7, the cartridge assembly may be provided as a reusable retainer that can be suitably connected, such as by threads, to a reusable pen base, and retainer. defining a chamber into which a disposable cartridge is loaded for use. Once the contents of the given cartridge are ejected by multiple uses of the injection pen, a user disconnects the retainer from the pen base, removes the spent cartridge from the open proximal end of the retainer, and discards that cartridge, and then inserts a replacement disposable cartridge into the retention element which is then reconnected to the base of the pen for use, cartridge replacement process that can be repeated whenever necessary. Furthermore, other cartridge assemblies may be used, such as a cartridge assembly that includes a disposable cartridge made of plastic and without an outer protective cover, and that is attached directly to the base of the pen, as well as a cartridge assembly that includes a replaceable cartridge, which is mounted or inserted into a chamber of the device, and a cover member for the chamber of the device that houses the cartridge, such as a different plug piece or access door that is slidably or pivotally connected to the device.

Referring further to Figures 3-6, the power pack includes a floating nut 60 located within the inner recess of the boom base 26 defined by the outer shell of the boom base. In the arrangement shown schematically in Figure 3, the distal end of the outer shell of the pen base includes a cartridge interface member 62 fixedly secured, such as by gluing, plastic press fit, or ultrasonic welding, to a rearwardly extending part of the casing body 64. Interface member 62 is internally threaded at 66 for connection to externally threaded reduced neck portion 44 to mount cartridge assembly 24 to the base of pen 26. External threading 63 of interface member 62 allows mounting of a main plug, not shown, of the injection pen 20. The power pack can also be used with other housing configurations.

Floating nut 60 is molded in one piece of plastic and includes a tubular body section 70, generally cylindrical, which is preferably keyed to the boom base housing to allow the nut to move in an axial direction therein. while preventing the rotation movement of the nut

ES 2 365 807 T3 inside the housing at any given axial position. A suitable keyway includes radially projecting keys 74 located adjacent the rear end of the body section of the nut 70 that engage within axially aligned keyways or keyways 65 formed in the body portion of the housing 64. In the embodiment shown, three angularly equidistant keys 74 are provided, but additional keys may be employed, or fewer keys including only a single key. In addition, the nut 60 can be keyed to the boom base housing by keys provided in the housing that fit within keyways formed on the outside of the nut.

The hollow interior 71 of the tubular body section 70 extends through the disc portion 80 of the nut 60. The hollow interior portion 71 located forward of the disc portion 80 is dimensioned to accommodate so that it can rotate freely to the shaft 46. A central aperture 81 defined by disk portion 80 is formed with internal threads 82 designed to engage external threading 124 of power set screw 120. A pair of drive clutch retaining members 85 are provided on opposite sides of the central opening 81. Each drive clutch retaining member 85 is a lip or closure portion 87 formed integrally with and projecting radially. inward from body section 70.

Floating nut 60 is pushed toward the forward end of boom base 26 by a pusher element that acts between nut 60 and, for example, the boom base housing. A suitable biasing element is a metallic helical compression spring 90 having a front end 91 that directly abuts the face of the annular end 72 of the body section 70, and a rear end 92 that directly abuts a sealing piece 93 protruding from the body portion of the housing 64. The rear end surface 67 of interface member 62 provides an axial abutment against which the front face 75 of each key of nut 74 abuts to limit forward axial movement of nut 60 by spring 90. In other arrangements they may make substitutions with alternative thrust elements, such as different types of springs and different materials of construction. Alternatively, the rear end of the pusher element may abut a component of the boom that is connected to, rather than being integrally formed with, the housing.

In the arrangement of Figure 3, the drive clutch 100 of the drive assembly is connected to the floating nut 60 to be axially and freely rotatable. The drive clutch 100 has a disc-shaped body 102 completely strapped by a radially outwardly projecting snap-fit ​​ring 104. When arranged as shown in Figure 6 during the device assembly process, movement of drive clutch 100 toward nut 60 results in snap-fit ​​ring 104 being pulled up from retaining elements 85. elastic clutch rings with the nut and the clutch being slightly elastic deformed until the press fit ring 104 axially passes the shoulder portions 87, at which time the pieces snap back into their original shape to axially capture the snap-fit ​​ring 104 between the flange portions 87 and a protruding surface portion 89 of the proximal face of the disk portion 80, which straddles to the central opening 81. The protruding surface portion 89 has a smaller diameter than the distal surface 106 of the drive clutch 100 to provide a smaller contact area to limit frictional resistance to rotation between them. In alternative arrangements, substitutions can also be made for other types of locking mechanisms to axially retain the drive clutch within the floating nut while allowing relative rotation between them, including different numbers of axially aligned flange portions or spike portions that are aligned. they extend rearward, from which a closure portion projects radially inward.

The body 102 of the drive clutch 100 defines a central opening 110 and has at least one inwardly extending V-shaped portion or key 112 projecting into the opening. Key 112 fits within a corresponding keyway channel 122 that extends longitudinally along the length of drive or guide screw 120, which includes external threading 124 that mates with threading 82 of floating nut 60. As shown in Figure 5, two diametrically arranged keys 112 fit within longitudinal keyways 122 located on opposite sides of the drive screw. Engagement of keys 112 with keyways 122 causes forced rotation of drive clutch 100 during injection to rotate drive screw 120, and similarly results in forced rotation of drive screw 120 during reset to rotate drive screw 120. drive clutch 100.

Drive clutch 100 is adapted to engage a rotatable drive member of the injection mechanism for transmission of torque. The radial outer region of proximal surface 113 includes a series of generally triangular shaped teeth 114, projecting axially, arranged in a crown, which teeth are structured and arranged to mesh with similarly shaped teeth 130 provided on the member. motor 135. Each tooth 114 includes an inclined side 116, and an axially aligned side 118 to which a force is directly applied by a tooth 130 during driving rotation of the drive clutch 100 by the drive member 135. In alternative arrangements, different torque transmission configurations, including flat plates that rely exclusively on friction for non-slip torque transmission, can substitute for the particular tooth configuration shown.

The rotatable motive member 135 rotates when the injection pen 20 is actuated to cause the fluid to be

ES 2 365 807 T3 ejected through needle assembly 27. Drive member 135 is schematically shown as annular disc 140 rotatably attached to a hinged sleeve 142 within the injection pen and through which the drive screw 120. Ring gear 140 includes forwardly extending teeth 130. The drive assembly can be driven by differently designed rotating drive members.

The power pack will be further understood in view of the following explanation of the operational aspects of the injection pen 20, beginning with the injection pen configured as shown in Figure 2, which occurs when a new cartridge assembly 24 is replacing a depleted cartridge assembly not shown. The user will first assemble the cartridge assembly 24 to the base of the pen 26.

Typically, a user will hold the reusable pen base 26 in one hand and the cartridge assembly 24 in the other hand, and will first manipulate the components so that the distal end 121 of drive screw 120 inserts into shaft 46 and the rod tip collar 38, and in contact with the rod tip base disc 37. The pen base 26 and the cartridge assembly 24 then move together mutually in an axial direction until the shaft 46 is axially inserted into the hollow interior of the pen base and the external threads of the reduced neck portion 44 They initially abut the internal threads 66 of the cartridge interface portion 62. In the course of this movement, rod tip 35 is first moved forward toward cartridge 22 to close any gaps that may have existed between it and plunger 34, and then drive screw 120 is pushed axially and screwed in. through the floating nut 60, while the drive clutch 100 is freely rotated with the drive screw 120 and into the floating nut 60. Drive screw 120 is therefore pushed back or reset, rather than forcing plunger 34 to slide within cartridge 22, due to the relatively low frictional resistance to drive assembly reset.

To continue assembly, the cartridge assembly 24 is then rotated relative to the base of the pen 26 to thread the components together. During an early phase of this rotation, within the internal volume of the housing, annular shoulder 45 contacts the end surface 76 of floating nut 60 which is in a forward axial position due to bias by spring 90. In alternative arrangements, other parts of the cartridge assembly, such as the rear end of shaft 46, may be the point of contact with nut 60. Also, instead of direct contact or engagement with the nut, the cartridge assembly may indirectly coupled to the nut, such as by an interposing member made of a low friction material. Continued threading of cartridge assembly 24 by the user moves floating nut 60 rearward against a resisting force generated by compression of spring 90. In particular, shoulder 45 slides along the surface of end 76 of the floating nut as the cartridge assembly rotates and moves axially, while the nut 60 moves axially without simultaneously rotating. The resistance force generated by spring 90, which increases as insertion progresses, reduces play between cartridge assembly 24 and pen base 26 to provide injection pen 20 with a more solid and improved feel. construction for the user, and to limit pen dripping that can occur during relative movement of the cartridge and drive screw.

The cartridge assembly 24 is fully assembled once it has been screwed in until the end face 43 of the barrel 42 abuts the distal face of the cartridge interface member 62, an arrangement shown in FIG. 4. When the cartridge assembly 24 is so mounted, the nut 60 and the retained clutch 100 are in a rearward axial position in which the teeth 114 of the drive clutch 100 are positively engaged with the teeth 130 of the drive member 135 at a non-slip shape, so that clutch 100 can be rotated by rotation of drive member 135.

Subsequently, and with respect to the injection pen 20 shown in Figure 1, once the knob 28 has been rotated to set a dose, the push by plunger of the button 30, which is mechanically interconnected with the sleeve 142 of the limb drive 135, rotates drive member 135 to rotate drive clutch 100 and thus drive screw 120, which threads through nut 60 to advance plunger 34 to push drug from needle-equipped cartridge assembly 24.

Referring now to Figure 7, parts of another injection pen equipped with a power assembly similar to that of Figures 2-6 are shown schematically. In this arrangement, the reusable pen base 226 is constructed in a similar manner to that shown in Figure 3, and further the drive assembly is the same as that shown in Figure 3, apart from the end 121 of drive screw 120 which is configured to support so that it can rotate an added base piece 123. Base piece 123 is attached so that it can rotate freely about screw axis 120 during use and serves to distribute pressure on plunger 34. The cartridge assembly in Figure 7 is in the form of a reusable retainer 230 with a disposable cartridge loaded in it, which cartridge is similar to cartridge 22 but lacks a rod tip 35. Retainer 230 can be connected to the pen base housing, such as through the threads shown at 232. Cartridge 22 can be inserted into, and removed for replacement from, the retainer through the open rear end. of the retainer when the retainer is not connected to the boom base 226. When a retainer 232 with a loaded cartridge 222 is mounted to the base of the pen 226, the floating nut 60 contacts the cartridge housing 32 directly, and the nut bias spring biases the cartridge 22

ES 2 365 807 T3 forward into the retainer against the inner surface of a not shown leading end of the retainer. This prevents cartridge 22 from moving relative to nut 60.

In yet another alternative arrangement not shown, it is not necessary for the drive clutch to be held by the floating nut, but is instead simply displaced into engagement with the drive member by, for example, abutting contact with the nut. floating. In such a configuration, the spring is operatively coupled to the drive clutch to bias it out of engagement with the rotating drive member when no cartridge assembly is properly mounted to the base of the pen. For example, the forward end of a spring may abut a washer member that holds the drive clutch forward, such as in contact with the floating nut.

Figures 8-11 show injection device assemblies that when actuated click, assemblies that are for a medication injector apparatus, such as the injection pen 20 of Figure 1. However, and although the descriptions of these assemblies below may refer to said pen 20 in general, said assemblies are not limited to being incorporated in pens similar to pen 20, but may be for incorporation in other injector apparatus of medication. The clickable injection device assembly of the invention can easily be adapted for many alternatively configured injectors in view of the explanation in this document, since the injection device assembly that when actuated emits a click of the invention described further below in theory can be mounted on the rotating drive sleeves of the injection mechanisms that are rotated by operating components configured differently than these injection mechanisms. Additionally, the injection device assembly that emits a click when actuated does not require the presence of a dose setting mechanism that allows variability in the amount to be administered.

As shown in Figure 8, one form of the clickable injection device assembly of the present invention includes a collar element in the form of a ring or clicking device, generally referred to as 240. In the following description of the operation of the part of the pen shown in Figure 8, said part of the pen is described as forming part of the pen 20 shown in Figure 1 for ease of explanation, but it will be appreciated that the pen shown in Figure 8 includes, for example, a power unit that is slightly different from that described above with respect to the boom 20, as well as a cartridge assembly comprising a reusable retention element 238, which is threadedly connected to the housing of the pen base, and a disposable cartridge 22 loaded therein.

Annular collar 240 defines a central hole through which drive sleeve 242 extends so that collar 240 is coaxially mounted on drive sleeve 242. At least one rib or key, such as a pair of diametrically opposed keys 244, they project inwardly into the center hole of collar 240 and slidably fit within longitudinally extending slots or keyways 246 on opposite sides of drive sleeve 242. Keying of collar 240 with drive sleeve 242 results in collar 240 being rotatably fixed but can move axially relative to drive sleeve 242. In an alternative embodiment, collar 240 may be keyed to drive sleeve 242 with keyways and coupling keys that are on the drive sleeve and collar, respectively.

The proximal face of collar 240 is formed with a ring of axially extending teeth 248. Teeth 248 mesh with mating teeth 250 that are molded into plug 252. The number of teeth on collar 248 and teeth 250 to which they engage need not be in a 1 to 1 ratio, as the device that emits a click when actuated may have, for example, one tooth out of every two. The sealing piece 252 is a ribbed additional component of the outer housing part 254, which outer housing is shown as an assembly of multiple component parts, so that the sealing piece 252 is fixed in rotation with respect to the housing of the pen while using the pen injection. The sealing piece 252 is axially fixed in the embodiment of Figure 8 by pressing by a spring 256 against an edge portion of the outer housing of the pen. In alternate embodiments, engagement teeth 250 may form part of a sealing piece formed in one piece with the outer shell of the pen.

Teeth 248 and 250 are configured so that when in meshed engagement, only one-way rotation of collar 240 with respect to seal 252, and thus to the pen housing, is allowed. During such relative rotation, the collar teeth 248, as they travel through the teeth 250, generate audible clicking noises. The unidirectional rotatability of collar 240 allows it to function as an anti-reverse mechanism for the drive sleeve and injection screw, as further described below. In alternative embodiments where an anti-kickback feature performed by collar 240 is not necessary, teeth 248 and 250 may be configured differently, so as not to prevent reverse rotation and to thereby allow bi-directional rotation of the collar.

The injection device that when actuated clicks 240 is biased in the proximal axial direction along the drive sleeve 242 by a biasing element, generally designated 258. In the embodiment shown, the biasing element is a pressure spring. Helical compression made of metal that is coaxially mounted on drive sleeve 242, but other types of springs or spring materials may be used.

ES 2 365 807 T3 construction as an alternative. During injection use of the pen, spring 258 supports collar 240 to provide injection clicks and rotational positioning. During fabrication, springs of varying strengths can be tested to select a spring that provides adequate clicking noise without modifying the seal or collar design.

The distal end of spring 258 abuts a proximally facing surface of a disc portion 260 that protrudes radially from drive sleeve 242. The distally facing surface of disc portion 260 includes a ring of extending teeth axially 262 that are used to transmit a rotational motion of the drive sleeve to a drive assembly that advances the injection screw. In the embodiment shown, which is intended to be illustrative and not limiting, the drive assembly includes a clutch 266 with proximal teeth 264 that mesh with teeth 262 on the disc portion when the pen is fully assembled, as shown in Figure 8. . Clutch 266 is keyed to threaded injection screw 270 by keys 268 which fit within diametrically arranged keyways 272 aligned longitudinally along the screw extending through drive sleeve 242. Clutch 266 is axially retained within, but being rotatable with respect to a floating nut, generally designated 275, as dowels 277 that snap onto the clutch during assembly. Floating nut 275 is keyed to the boom housing to be axially movable but rotatable. Floating nut 275 is biased distally by spring 256 when cartridge retainer 238 and cartridge 22 are removed from the pen base to disengage drive sleeve teeth 262 from clutch teeth 264 to allow resetting of the injection screw. When the floating nut 275 is moved distally during removal of the pen, for an injection mechanism shown in which the driver sleeve is not axially fixed, the driver sleeve 242 is moved distally by the action of the spring 258 against the disk portion. 260, but is prevented from engaging the clutch 266 by abutting the disc portion 260 against the not shown keys of the portion of the boom housing 255 to which the floating nut 275 is keyed.

The clickable injection device assembly of Figure 8 will be further understood in view of the following explanation of its operation within a pen such as pen 20. When the pen 20 is in the configuration shown in Figure 1, which is a ready state prior to the selection of the dose for injection, the teeth of the disk portion of the drive sleeve 260 and of the clutch 266 are engaged, and the teeth of collar 240 and plug 282 are engaged, as shown in FIG. 8. During dose selection or setting, spring 258 maintains the teeth of collar 248 in meshing engagement with the teeth of plug 252. Due to the unidirectional rotational ability of collar 240 and its keying to drive sleeve 242, the meshing of these teeth blocks the rotation of the drive sleeve 242. With the drive sleeve assembly locked in rotation, the clutch 266, and thus the drive screw 270 keyed thereto, cannot rotate, thus providing an anti-reverse feature of the injection screw. During the plunger push of the button 34 in the dose injection process described above, the drive sleeve 242, and therefore the collar 240 keyed thereto, is rotated in the direction allowed by the configuration of the collar teeth. 240. Rotation of the disk portion 260 of the drive sleeve 242 rotates the clutch 266 and thus the drive screw 270, which threads through an internal thread 279 of the nut 275 to advance in the distal direction to move the plunger. cartridge movable 22, for pushing medication from an outlet of the cartridge. As collar 240 rotates, it oscillates axially, against a proximal directed force applied by spring 258, as its teeth mount over the teeth of plug 250 and create audible clicks indicating the injection operation.

Referring now to Figures 9-11, there is shown another form of an injection device assembly that upon actuation emits a click of the present invention in a different injection pen shown partially. This injection device assembly that clicks when actuated is particularly adapted for an injection mechanism having a driving sleeve portion that moves axially during the injection operation. The clickable injection device assembly includes a ring-shaped collar element or clickable device, generally designated 290. Annular collar 290 defines a central hole 292 through which the tubular base 335 of the drive sleeve extends. At least one rib or key, such as a pair of diametrically opposed keys 294, projects inwardly into hole 292. Keys 294 fit within longitudinally extending keyways 340 on opposite sides of the base of drive sleeve 335 so that collar 290 is rotatably fixed but axially movable relative to the drive sleeve.

The proximal face of collar 290 is formed with a ring of axially extending teeth 296. The teeth 296 mesh with the mating teeth 347 molded into a seal piece 348 formed in one piece with the outer shell of the pen shown schematically.

Each tooth of the teeth 296 includes an axially aligned surface 297 and an inclined surface 298 that extends to the axially aligned surface of the succeeding tooth, which configuration of the teeth allows unidirectional rotation of the collar 290 with respect to the pen housing, allowing the collar to function as a non-return mechanism. During such relative rotation, the teeth of the collar 296, as they travel through the teeth of the pen housing 347, generate audible clicking noises.

IS 2 365 807 T3

The clickable injection device 290 includes a distal surface 300 which is sometimes abutted during pen operation by a radially aligned outer region 307 of a retaining ring, generally designated 305. The Ring 305 includes a central portion 309, angled forward, which fits tightly during boom mounting into a circumferential groove 343 formed in the base of drive sleeve 335. This connection causes the retaining ring 305 to follow the axial movement of the base of the driver sleeve 335 during operation, which axial movement is a function of the particular injection mechanism of the pen. The retaining ring 305 serves to limit the axial movement of the collar 290 when the drive sleeve is positioned axially as shown in Figure 9, such as during dose selection, by its outer region 307 that engages the surface. 300, thereby preventing disengagement of the collar teeth 296 from the housing teeth 347.

Collar 290 is urged in the proximal axial direction by a helical metal compression spring 320 oriented coaxially around the body of drive sleeve 335. Proximal end 321 of spring 320 fits around a reduced diameter neck portion 302 of collar 390. The end of the spring 321 is pressed on and retained by six ribs 303 spaced at regular intervals around the circumference of the neck portion.

The distal end 322 of the spring 320 fits around a reduced diameter neck portion 332 of a radially projecting torque transmitting member 330 of the drive sleeve, generally designated 325. The drive member 330 is the portion of the drive sleeve. drive sleeve that transmits the rotational movement of the drive sleeve to a clutch 350 keyed to drive screw 354. Six regularly spaced ribs 331 around neck portion 332 are biased toward distal end 322 of spring 320 during boom assembly to retain spring 320 on drive member 330. The distal-facing surface of drive member 330 includes distally and axially extending teeth 333 that mesh with teeth on clutch 350 when the pen is assembled for use.

In the embodiment shown in Figures 9-11, the drive sleeve is a two-piece assembly, as the radially projecting drive member 330 is configured to allow limited axial movement relative to the tubular base 335 of the drive sleeve, base. that is rotated when the pen injection mechanism is actuated. This relative movement capability helps prevent clutch binding when mounting a cartridge assembly to the base of the boom. In particular, during the assembly of the cartridge assembly, in the state that the clutch mechanism is tooth-to-tooth, the drive member 330 can be retracted, which allows the cartridge assembly to be fully installed without blocking or damaging the teeth. clutch, and any tooth-to-tooth condition that remains after installation is automatically addressed with boom priming. This relative movement capability also allows axial movement of the tubular base of the drive sleeve during the injection operation, which movement is a function of the overall injection mechanism of the pen.

Within a central hole 334 of drive member 330 through which tubular base 335 fits, a pair of diametrically opposed keys 337 project radially inward. Keys 337 fit within longitudinally extending keyways 340 so that member 330 is rotatably fixed but can move axially relative to the base of drive sleeve 335. A pair of diametrically opposed snap fasteners or ribs 338 also project into bore 334 at locations offset by ninety degrees from keys 337. During manufacturing assembly of driver 330 to base 335, ribs 338 are snap fit at the recesses 341 formed in the periphery of the base of the drive sleeve 335 and in spaced relation to the distal end 342. The recesses 341 extend in the axial direction greater than the thickness of the ribs 338 to allow limited axial movement of the drive member 330 relative to the base 335. The push-fit connection prevents the drive sleeve assembly from being axially separated when a medication cartridge is removed from the pen base, and further ensures that forward travel of the drive member 330 along the base of the drive sleeve is limited. 335 to assist in disengagement of drive member 330 from clutch 350 when a cartridge assembly is removed.

The teeth 333 of the drive member 330 engage with a clutch of a drive assembly used to move the injection screw distally. The drive assembly shown in Figure 9 has a clutch 350 keyed internally to a threaded drive screw 354 that extends through the base of drive sleeve 335. The clutch 350 is connected to a floating nut 360 fixed in rotation which is engaged by means of thread to drive screw 354. Rotation of clutch 350 by drive sleeve 325 rotates drive screw 354, which threads through nut 360 to advance in the distal direction past the end of the reusable pen base to move movable plunger 365 out of the way. cartridge 367 so that medication is pushed from an outlet of the cartridge. Floating nut 360 is biased distally by spring 369 as the cartridge assembly is withdrawn to disengage the drive assembly from teeth 333 on the drive sleeve to allow resetting of the injection screw. This powertrain has been more fully described above. In devices with the clickable injection device assembly of the invention other drive assemblies may be used with a clutch that operatively engages the drive sleeve member 330 when the pen is assembled for use.

IS 2 365 807 T3

The clickable injection device assembly of Figures 9-11 will be further understood in view of the following explanation of its operation within the pen. When the pen is assembled as shown in Figure 9, the teeth 333 of the drive sleeve member 330 and the clutch 350 are engaged and the teeth of the injection device click 290 and the pen housing are coupled. During dose selection, the base of the driver sleeve 335 is retained proximally, such as by a spring not shown, causing the retaining ring 305 to abut the surface of the collar 300 to hold the teeth 296 of the device as being When actuated, it clicks into a gear engagement with the teeth of the 347 housing. Due to the keying of the collar 290 to the base of the drive sleeve 335, this gear teeth locks the base of the drive sleeve 335, and thus the drive member 330, in rotation due to its keying to the base 335. With the drive sleeve assembly locked in rotation, clutch 350, and therefore injection screw 354 keyed thereto, cannot rotate, thus providing an injection screw anti-return feature.

When the injection mechanism is actuated manually during an injection use of the pen with increased dose selection, the base of the driver sleeve 335 is first moved distally to move the retaining ring 305 distally so that the collar 290, subjected to a greater force than the biasing force of spring 320, can be moved distally. The body of the drive sleeve 335 then begins to rotate, and the teeth 296 of the collar 290 move in and out of engagement with the teeth of the housing producing injection clicks. The rotation of the drive sleeve also causes the drive clutch 350 to rotate, which threads the injection screw 354 through the floating nut 360. During this injection process, if the floating nut floats slightly proximally, the compressed spring 369 pushes it back toward the distal end of the pen to end the injection.

In one form shown in the block diagram of Figure 12, an apparatus indicating a therapeutic dose is housed in a delivery device 420 and uses an automatic container recognition element 422, a dosable quantity identifier 424, a controller 426, and a 428 screen. One type of delivery device for which the system is particularly well suited is an injection pen, but other types of portable devices, such as a pulmonary device or inhaler, can be similarly equipped.

The automatic container recognition element 422 functions first to recognize a characteristic of a container insert in the delivery device 420, which characteristic refers to a concentration of the drug within the container, and then to input that information into the controller. 426, as shown in 430. The dosable amount identifier 424 functions first to detect the readiness to which a user has manipulated the dose setting mechanism of the delivery device 420 to prepare the device to deliver a first volume of the drug, and then to introduce that information in controller 426, as displayed at 432. In response to the input information, controller 426 calculates the therapeutic dose to be delivered and instructs display 428 via line 434 to visibly present that dosage to a user of delivery device 420.

The delivery device with the ability to indicate the therapeutic dose of Figure 12 is shown in Figure 13 as a reusable injection pen, generally designated 440. As is conventional in reusable devices of this type, the injection pen 440 includes a cartridge assembly, generally designated 442, which is connected to a base of the pen, generally designated 444, which houses the injection setting mechanisms. the dose and injection which, when actuated, cause an amount of the drug to be selected and then expelled from cartridge assembly 442 through injection needle assembly 467.

One form of cartridge assembly 442 is further shown in cross-sectional view in Figure 14 and is the same, except for the identifier described below, as cartridge assembly 24 of Figure 2. Therefore, the Cartridge assembly 442 includes a cartridge 446 with a glass housing 448 that defines an internal volume filled with medication. The cartridge includes slide plunger 449, rod tip 452, plug 464, and septum 466. Cartridge 446 is further protected by an outer casing or barrel 458 that includes an internally threaded reduced neck portion 460 and an additional reduced rear axle 462. External threads 468 on plug 464 allow mounting of injection needle assembly 467 that pierces septum 466.

The automatic cartridge or container recognition element 422 of the injection pen 440 includes an identifier associated with the cartridge assembly 442 that is designed to operate with a sensor that signals the controller 426 within the base of the pen 444 based on the identifier detected. As described in US Patent Nos. 5,954,700 and 6,110,152, the identifier can take many forms and can be used to indicate various facts to the user.

In one form, the identifier is used to represent the concentration of the therapeutic content of the cartridge assembly, and the concentration identifier that is disposed on the axis of the outer housing 462 of the cartridge assembly 442. The concentration identifier has specific characteristics, such as as dimensional and spatial characteristics, recognizable by the sensor of the cartridge automatic recognition element

IS 2 365 807 T3

422. In alternative arrangements, and with corresponding modifications to the cartridge auto-recognition element sensor 422, the identifier may be located on other parts of the cartridge assembly, including, but not limited to, the cartridge housing 448, and the tip of the cartridge. rod 452, and can further be used to represent, for example, which of the possible different types of insulin is contained in the cartridge assembly.

The concentration identifier is permanently affixed to the cylindrical outer surface of shaft 462. For cartridge recognition systems that detect or otherwise read the identifier with elements other than electrical contacts located radially outward as described below, for example when the concentration identifier is adapted for use with optical sensors or magnetic, the identifier does not need to be exposed on the periphery of the axis 462, and may be positioned differently, such as attached to the inner surface of shaft 462.

As further illustrated in the various arrangements shown and described with reference to Figures 15-17, the cartridge concentration identifier is shown to be formed from a single strip of electrically conductive material fixedly associated with shaft 462. The strip shown extends the entire circumference of the shaft, but may span only a portion of the circumference if the associated sensor contacts of the container recognition element 422 described below are configured to achieve a satisfactory connection despite one or more circumferential gaps in the strip. The conductive strip may be in the form of a printed conductive ink pad applied to the shaft, however, other means may be employed to achieve the identifier strip. For example, the strip may be a corrugated metal strip, or a conductive plating of an insert of molded material on the shaft, a conductive paint, or a printed ink pad, or a metallic self-adhesive label, or a non-conductive adhesive label on the one that the appropriate electrically conductive pattern has been applied.

Referring now to Figures 15-17, the axes 462a, 462b, and 462c of three different types of cartridge assemblies 442a, 442b, and 442c are shown each compatible with the 444 pen base. The content identifier type shown that being used on axes 462a, 462b and 462c uses the dimensional aspect of the width of the conductive strip, together with the spatial aspect of the placement of this strip on an axis, to represent the contents of the cartridge. This type of content identifier has particular applicability for identifying the concentration of hGH (human growth hormone), which has a limited number of common concentrations, and therefore the three cartridge assemblies shown in Figures 15-17 contain each hGH in a different concentration. In other types of content tags, the dimensional appearance of the tag strip may be different from the width, such as the thickness or texture of the strip.

In Figure 15, which depicts a first concentration, a conductive strip 472 having a relatively small width, such as about 4.8 mm, surrounds the shaft 462a of the cartridge assembly 442a near the distal end of the shaft that is adjacent to the neck. threaded 460a of the barrel. In Figure 16, which depicts a second concentration, a conductive strip 474 having a relatively small width, such as about 4.8 mm, surrounds the shaft 462b of a second cartridge assembly 442b near the proximal end of the shaft. Although the widths of the strips 472 and 474 are identical to reduce the number of differently constructed parts required to make the various cartridge assemblies, as will be appreciated from the following explanation of the operation of the device, different widths may be used to strips 472 and 474, provided that appropriate electrical circuits result between the sensors. Finally, in Figure 17, depicting a third concentration, a conductive strip 476 having a relatively large width, such as approximately 7.1 mm, surrounds the shaft 462c of a third cartridge assembly 442c and covers almost the entire axial length. From the axis. The axial region of shaft 462c covered by strip 476 is the same as that which would be covered by strips 472 and 474 if they were positioned on shaft 462c at the same locations as strips are positioned on shafts 462a and 462b, respectively.

Once any of the cartridge assemblies shown in Figures 15-17 has been properly mounted to the injection pen 440, such as by threading that cartridge assembly onto the pen body 444 of Figure 13, the identifier The content of that assembled cartridge assembly provides a conductive path between a series of sensor contacts within the device that are spaced apart along the axial length of the inserted shaft. The various widths and locations of the content identifiers on the various cartridge assemblies provide different conductive paths between the sensor contacts.

For example, as shown schematically during operation in Figure 18, the sensor includes electrical contacts 480, 481, and 482. Although these sensor contacts are shown in Figure 18 as in exact axial alignment, each of the sensor contacts 480-482 may be angularly spaced from the other sensor contacts, such as within a 60 ° circumference span or 120 ° spacing, or other such angular spacing that may be possible within the internal recess of the pen base. Furthermore, each contact of the sensor could naturally comprise a plurality of contacts in parallel circuit and positioned in the same axial location of the shaft. The sensor contacts may be springy metal pins that extend from a sub-mounting base mounted so that it can pivot in, for example, the housing, and the circuitry in the base is electrically connected to a 426 controller circuit board. base of

The ES 2 365 807 T3 subassembly is biased so that it can rotate so that the shaft contacting portions of the metal pins are in a radially retracted position when no cartridge assembly is mounted to the base of the 444 pen. When the shaft is inserted during the connection of the cartridge assembly 442 to the base of the 444 boom, through movement of the shaft, or a moving part of the base of the boom that can be coupled to the shaft, such as a nut described above, a pivot arm of the sub-mount base is contacted, which causes the sub-mount base to rotate, so that the contact parts of the pins move in communication with the content identifier. In an alternative arrangement, instead of the pivoting sensor contacts, the pins may be spring or leaf spring type metal pins that are pushed radially inward into contact with the shaft and are mounted, for example, on the shaft. boom housing base or a movable part within the boom base housing itself 444, pins that slide along the shaft when the shaft is inserted during connection of the cartridge assembly 442 to the base of the pen 444.

Controller 426 processes related data for which sensor contacts within injection pen 440 are in communication with the content identifier conductive strip and derives information from a look-up table to essentially read what is represented as within the cartridge assembly. For example, sensor contacts 480 and 482 are in direct circuit to controller 426 via lines 484 and 486, lines that can be patterns printed on a circuit board of controller 426. Sensor contact 481, similarly, It is in circuit with controller 426 via line 488 which is grounded at 490. When the cartridge assembly 442b with content identifier 474 is loaded as shown in Figure 18, the grounded 481 sensor contact is in communication with the identifier 474, and the conductivity of the identifier 474 is used to ground. sensor contact 482 and thus line 486 to controller 426. Since sensor contact 480 is not in communication with identifier 474, line 484 is not grounded. As a result, controller 426 has been effectively instructed that line 484 remains open, while line 486 has been closed, and controller 426 matches this input with a certain concentration of hGH, such as 12 mg, that is present within of the loaded cartridge assembly 442b. (This concentration, as well as other hGH concentration referenced in this document, is stated in units of mg, as opposed to units of mass by volume as might otherwise be expected, since it is how it is normally referred to. at these concentrations for hGH, such as by doctors to their patients. Said indication is a result of the numerical value that refers to the mass in mg of the lyophilized drug before its reconstitution, which results in the content of the cartridge being in liquid form. The concentration in mg / ml can be easily obtained by dividing the referenced milligram mass by the 2.88 milliliter volume of the cartridge contents when reconstituted). Similarly, when cartridge assembly 442a with content identifier 472 is loaded, grounded sensor contact 481 is in communication with identifier 472, and identifier 472 is used to ground the contact of the sensor 480 and line 484 to controller 426, but the contact of sensor 482 and line 486 are not grounded, thus resulting in that controller 426 is instructed that line 486 remains open while line 484 has been closed, so that controller 426 matches this input with a different hGH concentration, such as 6 mg, that is present within the cartridge assembly 442a loaded. Similarly, when cartridge assembly 442c with content identifier 476 is loaded, the grounded 481 sensor contact is in communication with identifier 476, and identifier 476 is used to ground sensor contacts 480 and 482. and lines 484 and 486 to controller 426, thereby resulting in indicating to controller 426 that lines 484 and 486 have been closed, so that controller 426 matches this input with a different hGH concentration, such as 24 mg, that is present within the loaded cartridge assembly 442c. Finally, when no cartridge assembly is loaded, or a cartridge assembly without an identifier or with a faulty identifier is loaded, the controller 426 is indicated that lines 484 and 486 each remain open, so that it is not available. no concentration information as input.

It will be appreciated that the cartridge recognition system could have more or less than the three contact points shown in Figure 18, and could use recognizable electrical signals other than ground, such as a small voltage, to activate the identifiers of contents. Furthermore, the cartridge assembly may be configured differently, as is known in the art, and as described above. In an embodiment using a disposable cartridge and a reusable retainer, the content identifier will be provided on the disposable cartridge, and the base of the 444 pen will be modified accordingly to allow recognition of that cartridge, such as such as by incorporating part of the recognition system, for example wiring and electrical contacts, in the retention element, or by configuring the components of the base of the boom, such as contacts, to extend into the retention element chamber.

Referring now to FIG. 19, one form of a dosable quantity identifier of the injection pen 440 is shown schematically. The dosable quantity identifier 424 includes a rotating matrix, generally designated 500, and a series of sensors, generally designated 502, which together are arranged to identify the pen mechanism settings used at least in setting the dose. , as well as preferably in the injection of the dose after the establishment of its dose. Various mechanisms for setting and injecting a dose are known in the injection pen art and, therefore, are not fully explained in detail herein. Also, as the identifier of the

ES 2 365 807 T3 dosable amount can easily be adapted for such mechanisms and for newly developed ones in view of the explanation provided herein, the details of such mechanisms further explained herein are intended to be illustrative and not limiting. Furthermore, in alternative arrangements, known design dosable quantity identifiers communicating with a controller may be substituted for the rotating array / sensor array within the therapeutic dose indicating apparatus.

Rotating array 500 and sensor array 502 are operatively connected to first and second injection pen components 440 that undergo relative rotational movement during actuation of the dose setting mechanism by a user to select a volume. desired to inject.

In the embodiment of Figure 19, the dose setting mechanism includes a rotary selector 506 in which the rotary die 500 is incorporated. The selector 506 is rotatably attached to an exposed knob 508 that can be rotated by the user to select the dose to be administered by using the injection pen. In the described embodiment, the selector 506 when rotated by the knob 508 undergoes translation out of the base of the boom 444, or to the right from the perspective of an observer of Figure 13, during the increase of the selection of the dose in preparation for injection of the dose. However, the die need not be in a selector that undergoes translation in this way, but may be in other rotating components such as a driver sleeve. Furthermore, although only one of the first and second components of the relatively rotatable pen is part of the dose setting mechanism in the embodiment of Figure 19, as is the other of these components to which the sensor array 502 is connected. may be the outer shell of the pen base 444, the first and second components may each be part of the dose setting mechanism in other arrangements.

Shown extracted from selector 506 and in two dimensions in Figure 20, matrix 500 is arranged with data in a rectangular series made up of multiple rows and columns that intersect orthogonally. The number of columns is a function of the internal mechanisms of the injection pen, and corresponds to the number of rotation positions within one of its revolutions in which the selector 506 can be adjusted so that the injection pen delivers different volumes of medication. . The movement of the selector 506 between the adjacent rotary positions corresponds to a change in a dose volume unit of the amount to be injected by actuating the pen, and such change is known as a click due to the setting mechanism, as a result of its configuration, which produces an audible clicking noise during such movement. The actual amount of such a dose volume unit, eg 0.024 ml, is a function of the design of the dose setting mechanism, as is known in the art.

The matrix equipped with the data 500 is in the form of the presence or absence of an electrically conductive material at the intersections of the rows and columns, electrically conductive data points that are shown contiguous or joined to form a structured pattern 501 and arranged in conjunction with the 502 series sensor contacts to convey the information to the controller 426 of the pen 440. The connection allows an electrical signal supplied to a single data point in pattern 501, such as a ground connection from that point, to travel throughout the entire pattern, as further described below.

Each of the six rows 509, 510, 511, 512, 513, and 514 of matrix 500 extends around the entire circumference of selector 506. The twenty-four columns 516, 517, 518, 519, 520, 521, 522, 523 , 524, 525, 526, 527, 528, 529, 530, 531, 532, 533, 534, 535, 536, 537, 538 and 539 of the matrix are of equal width, so that each covers 15 ° of the circumference of the selector, and are aligned in parallel with the axial length of the selector 506. In the arrangement shown, column 516 is not equipped with any electrically conductive data points and is formed by a circumferential gap between the ends of the portion of the conductive pattern that otherwise fill row 509 (i.e. columns 517-539) when matrix 500 surrounds selector 506. The design of the twenty-four column matrix allows twenty-four different rotary positions of selector 506 to be recognized. However, fewer or more columns of the twenty-four shown may be provided. In addition, a different number of matrix rows than the six shown may also be used, as long as a suitable pattern recognizable by the 526 controller results.

The electrically conductive pattern 501 of the die 500 can be fabricated by double injection molding a material that can be electrocoated, such as charged styrene plastic, into an electrically non-conductive or insulating sleeve, which is then molded into it is electroplated with a conductive material, such as successive layers of copper, nickel, and then gold, so that it is electrically conductive. After electroplating, the sleeve is securely attached to selector 506. To facilitate fabrication, such as to provide a necessary attachment point to position the required pattern, conductive pattern 501 of die 500 may include an extension not shown beyond of the rows or columns of the matrix, but an extension not used by the 502 sensor series. In alternative arrangements, the die pattern may be manufactured in another shape, such as a sheet metal die insert molded into a sleeve, or such as in ways similar to those described above with reference to cartridge content identifiers, for example by a metallic pattern on a non-conductive self-adhesive label or flexible circuit board attached to the selector, or by conductive paint or printed conductive ink pad applied directly

ES 2 365 807 T3 to the selector.

Sensor array 502 is operatively coupled to array 500 to detect array data. For the electrically conductive matrix pattern 501 shown in Figures 19 and 21, the sensor array 502 includes radially extending elastic metal or leaf spring-type contacts 546, 547, 548, 549, 550, and 551. inwardly from a cylindrical base sleeve 544 coaxially disposed on selector 506. Each of the sensor contacts 546-551 contacts the matrix 500 within a different row, and in the arrangement shown, the sensor contacts 546, 547, 548, 549, 550 and 551 are aligned respectively with the rows of the matrix 509, 510, 511, 512, 513 and 514. The sensor contacts 546 and 549 are installed in a first circumferential position of the base sleeve 544, the sensor contacts 547 and 550 are installed in a second circumferential position of the base sleeve 544 that is 120 ° apart from the position of contacts 546 and

549, and the sensor contacts 548 and 551 are installed in a third circumferential position of the base sleeve 544 that is 120 ° apart from the positions of both the contacts 546 and 549 and the contacts 547 and

550. This uniform angular spacing of the sensor contacts around the die serves to center the die and limit frictional resistance. For this 120 ° spacing, when selector 506 is oriented in rotation with respect to array of sensors 502, so that contacts 546 and 549 each abut array 500 within, for example, column 516, the Contacts 547 and 550 each abut matrix 500 within column 524, and contacts 548 and 551 each abut matrix 500 within column 532.

When sensor contact 546, which serves as the grounding contact as described below, is aligned with column 516, in the embodiment shown this is the "out" or "zero" position of the selector. When the pen is handled so that no volume of medicine is delivered by operating the pen injection mechanism, the selector will be in this exit position. In the home position, the ground connection is not electrically connected to any of the other 547-551 contacts. The pattern of the matrix can be adapted to indicate this starting position even though, for example, the conductive pattern fills the entire row 519 including column 516. For such a matrix pattern, the pattern would also be configured to not be in contact with any of the other contacts of sensor 547-551 when the contact of sensor 546 was aligned with column 516.

The matrix pattern 501 shown in FIG. 20 is designed in a complementary manner for this contact arrangement. The matrix pattern 501 uses a Gray code encoding scheme to reduce the risk that an error will not be detected in the detection of the selector position. In the coding scheme of the Gray code, the pattern is configured in view of the position of the sensor, so that the rotational movement of the selector, in any direction and in an amount equal to one column, makes only a single of sensor contacts 547-551 switch their electrical circuit relationship to the pattern, the only switching that can be monitored by the controller (i.e. only one sensor contact changes from not being in contact with the pattern to being in contact with the pattern, or vice versa, when turning the dial causes each sensor contact in its given respective column to move to a column on either side of a given column). In the arrangement shown, each of the twenty-four fixed rotational positions of selector 506 with respect to a sensor sleeve 544 results in a single set of information being recognized by operation of sensor contacts 546-551.

It will be appreciated that column positions of the sensor contacts different from the three sets 120 ° apart described above, for example all sensor contacts 546-551 that are aligned with one of the columns of the matrix, may be used, provided they are made appropriate modifications to the conductive matrix pattern.

To maintain proper alignment of the sensor contacts with the array pattern 501, the array of sensors 502 and the rotary array 500 are free to rotate and axially fixed to each other. For the rotating array / sensor array shown in Figure 19, the sensor array 502 may be keyed to, for example, the boom base housing 444 so that it is free to translate with, but not rotate with, selector 506 when the selector is rotated and thus caused to move during dose setting. Connections not shown between selector 506 and sensor array 502 can be used to make the sensor array translate with the selector.

The sensor contacts 546-551 of the 502 series are each circuit connected to the controller 426 as depicted abstractly on line 432, so that the sensor input can be used by the controller 426 to bypass the positioning of the matrix using a look-up table in a manner similar to that described above with respect to the automatic recognition element of the container. For example, during use, a ground signal is sent to sensor contact 546, which contacts and grounds matrix pattern 501 in all rotary selector positions except when the sensor contact 546 is aligned in matrix column 516. When the electrically conductive matrix pattern 501 is grounded in this manner, each of the sensor contacts 547-551 that are in contact with the conductive matrix pattern 501 is also grounded. The set of ground / ungrounded signals received by controller 426 through line 432 for all sensor contacts is used to derive the rotational position of the matrix 500, and thus that of the selector 506, with

ES 2 365 807 T3 with respect to sensor series 502. When sensor contact 546 is aligned with matrix column 516, none of the contacts are connected to ground, information that is also recognized by controller 426 as indicative of a particular position of the twenty-four rotational positions of the selector 506.

The data in the matrix 500 that includes areas of electrically conductive material are due to said data that serves to complete electrical circuits with the electrical contacts of the sensor. In alternative arrangements, different forms of matrix data can be used with corresponding modifications for the sensor array. For example, if optical or magnetic sensing elements are to be employed in the 502 sensor array, the data in the array may be marks or magnets, as appropriate.

The sensor array / array shown in Figure 19 is simply one suitable shape and can be arranged differently. For example, the locations of the array of sensors and the array can be reversed, so that an array of sensors 502 looped to the controller 426 is mounted on the selector 506 and arranged to mate with a rotating array arranged on the inner circumference. coaxial sleeve 544.

In addition, and as further described with reference to the embodiment of Figures 23-30, both the array and the array of sensors may be arranged on the reusable pen base components that rotate at different times during setting of the reusable pen. the dose and injection usage of the 440 injection pen. To facilitate signal communication between the controller 426 and said series of rotation sensors, a slide guide assembly is arranged between them. As shown schematically in FIG. 22, a series of sensor contacts 546'-551 'are installed in a first pen component 558 shown partially mounted coaxially over a second pen component 559 partially shown. The 558 boom component is completely strapped together by six electrically conductive metal bands 560-565 that fit into channels on its outer radial periphery. Bands 560-565 are in contact with the outer ends of sensor contacts 546'-551 ', respectively, which extend through the radial thickness of component 558. Sensor contacts 546'-551 'are structured and arranged similarly to sensor contacts in the array of Figures 19-21, and contact a rotating die not shown, similar to die 500, that surrounds the component of pen 559. The 570 slide assembly includes six elastic electrical contacts 571-576 that have free ends that slide along the 560-565 bands as the 558 boom component rotates, and that slide contact results in an electrical connection between the sensors 546-551 'and the slide guide contacts 571-576 at any position of rotation of the pen component 558 with respect to the slide guide assembly 570.

If the internal mechanisms of the injection pen are configured so that the 558 and 559 pen components do not translate or move axially during operation, the 570 slide assembly can be mounted on a stationary component on the base of the injection. the pen, such as a microprocessor containing a flexible circuit board attached to the injection pen housing and serving as a controller 426. The contacts of the slide 571-576 are connected in the circuits on this circuit board routed to the controller microprocessor. For this type of slide assembly assembly, apart from the limited axial play as may be required for the internal mechanism parts of the injection pen, the 570 slide assembly is axially and rotatably fixed within the base. pen 444. If the 558 and 559 boom components move together during boom operation, the 571-576 slide contacts are wired to the 426 controller and the 570 slide assembly is keyed to, for example , the outer shell of the pen and is connected to the pen component 558 to translate, but not rotate, with the series of sensor contacts 546'-551 '.

The injection pen controller 426 that processes the signals from the sensor contacts of the automatic recognition element of the container 422 and the identifier of the dosing quantity 424 to determine the display information can be constructed and installed within the base of the pen. 444 in any suitable way known in the art. In one arrangement, the 426 controller includes a battery-powered, programmable microcontroller mounted on a main flexible printed circuit board that is generally U-shaped and flexible to fit within the pen base housing and to provide a recess into which the internal mechanism parts of the pen base 444 extend. The flexible circuit board is connected to the housing with locating pins and adhesive. In an alternative arrangement, the microprocessor can be replaced by an application-specific integrated circuit or ASIC.

The injection pen display 428 is operatively coupled to the microcontroller 426 and is visible through a transparent window in the pen base housing 444. The display 428, such as a liquid crystal display, visibly presents useful information to a user for the actuation of the injection pen. For example, as best shown in Figure 13, the microcontroller 426 causes the display 428 to present at 580 information about the drug within the contained cartridge, recognized by the automatic recognition element of the cartridge 422, at 582 the amount of agent Therapeutic that the injection pen presents ready to be administered by actuation of the injection mechanism of the pen 440 as further described below, and at 584 the remaining power of the battery that supplies in this document to the electronic components of the injection pen 440. The information shown at 580 refers to

ES 2 365 807 T3 to the drug concentration, as further explained above, but other types of information may be provided. The units of the dose to be administered are shown in Figure 13 printed on the bottom of the housing window at 586, but may be part of the screen controlled by the microcontroller 426.

The design of the therapeutic dose indicating apparatus in the injection pen 440 will be further understood in view of the following explanation of its operation. While the cartridge assembly 442 is mounted to the base of the pen 444, the controller 426 remains in a ready state with all display elements disconnected so as not to present any information to a user. In this ready state, the controller 426 processes the signals received from the sensor contacts of the automatic recognition element of the cartridge 422 to identify, for example, the concentration of the drug contained within the cartridge assembly as represented by the identifier strip. In this ready state, the controller 426 also processes the signals received from the dosable quantity identifier sensor contacts 424 to identify the position of the matrix 500 with respect to the array of sensors 502.

Controller 426 advances from ready state to operational state, and display 428 is thus activated, when controller 426 detects additional user action on pen 440. For example, such detecting action will typically be an acknowledgment of that array 500 is moving relative to array of sensors 502 during user manipulation of the dose setting mechanism. Another action that may be detected is the actuation of an on / off button not shown which may be located at the base of the pen 444, or as part of the control 508 of the injection mechanism.

When advancing to the operational state, the controller 426 causes the concentration identified with the automatic recognition element of the cartridge 422 to be displayed at 580. If the controller 426 does not recognize any concentration information, an error message such as as or no message at all, rather than any numerical value of the concentration. Recognition failure can result from a cartridge assembly being completely missing from, or not properly mounted to, the 444 pen base, or a cartridge identifier being damaged or missing from the assembly, or from a failure internal in the circuit of the cartridge automatic recognition element. When concentration information is not automatically recognized, the concentration used by controller 426 can be user configurable. For example, the set button 588 shown in Figure 13 is wired into the controller 426 and can be pressed to select, and have displayed at 580, any of the standard concentration values, such as 6, 12, and 24 mg in the case of hGH, pre-programmed into the 426 controller.

While the controller 426 is in the operational state, when the knob 508 is rotated by a user to set the dose to be delivered, the controller 426 continuously receives a real-time input from the quantity identifier sensor contacts. metering 424 to identify the position of the matrix 500 with respect to the array of sensors 502. Controller 426 processes the input to determine to which position selector 506, and therefore matrix 500 in the arrangement shown, has been rotated from the "zero" position of the selector to which no volume of medication will be delivered. if the pen injection mechanism is actuated. For example, if the "zero" position of selector rotation is when sensor 546 engages column 516, controller 426 recognizes when sensor 546 is in engagement with each column 517539 to determine what percent of revolution of a selector has been made. Typically, automatically during, or manually after injection of the set dose, the dial returns to its original "zero" position for later use. However, the controller 426 can be designed to determine the dose setting based on any starting point of the selector.

Controller 426 detects the rotational position of the dose setting selector via the array / sensor array interface if the selector has already been rotated, or the selection has already been increased, so that the set dose is increased. , or the selection has already been lowered to decrease the set dose. Additionally, controller 426 is programmed to count one or more complete selector revolutions during dose setting. During dose setting, by recognizing the position of the array relative to the array of sensors in the orientation from which the dial is being rotated, the controller 426 recognizes which direction the dial is being rotated during the movement to the “zero” rotational position of the selector. Specifically, if the selector "zero" rotation position is when sensor 546 engages column 516, controller 426 recognizes that the set dose is increasing if sensor 546 reaches column 516 immediately after being in column 539 , and that the set dose is decreasing if sensor 546 reaches column 516 immediately after being in column 517.

For example, with the selector initially set to the selector "zero" rotation position, during movement of the selector to increase the dose when that selector "zero" rotation position is reached for the first time and the movement of the selector continues to increase the dose, and then the rotary position “zero” of the selector is reached a second time and the dose selection increase continues, When the controller 426 detects through the sensor array / array that, for example, a user has stopped rotation of the selector when the selector reaches the sixth rotational position from the "zero" position, the controller 426 recognizes that A unit volume dose of fifty-four has been established for injection (i.e. two

ES 2 365 807 T3 complete revolutions each of twenty-four positions or unit volumes in the arrangement shown plus the additional six positions). If a dose is initially set to too large an amount by a user who then reduces that dose setting prior to injection, the decrease in dose selection through the "zero" rotation position achieved by one or more Complete revolutions of the selector will be counted by controller 426.

The dose volume that the controller 426 identifies with the dosable amount identifier 424 is used to display the actual therapeutic amount to be injected. Specifically, the controller 426 essentially multiplies the concentration displayed at 580 by the volume set by the rotation of the selector 506 and causes the injectable amount of the therapeutic agent to be present at 582. The multiplication step described above is typically performed by controller 426 referring to a lookup table filled with data based on the therapeutic concentration and the number of selector "clicks" selected. The display at 582 presents the injectable amount at all times during the entire dose setting process. For example, when each "click" corresponds to a unit dose volume of 0.024 milliliters, when the cartridge concentration is 6 mg as explained above, each movement to increase the dose of selector 506 by an amount of 15 degrees , or a click, causes the 582 display to increase by 0.05 for the milligram labeling shown, and similarly, when the cartridge concentration is 24 mg, Each movement of the selector to increase the dose of a click of the selector 506 causes the display 582 to increase by 0.20 for the milligram labeling shown. Therefore, at all times, the amount of therapeutic agent presented at 582 is the medically significant amount actually injectable by actuation of the injection pen 440. The user does not need to perform calculations based on the concentration of hGH loaded in cartridge assembly 442 to know how much hGH is being injected.

In addition, the amount displayed at 582 also works throughout the injection (that is, it shows the amount that remains to be injected yet) if the pen components in which the array and array of sensors are arranged are designed to properly rotate a relative to each other during injection.

Once the injection pen 440 has been used to inject the set dose, such as by pressing axially on the knob 508 and moving the selector 506 back toward the base of the pen 444, the controller 426 automatically returns to an off state. , and the screen display elements 428 all turn off, after a certain period of inactivity time. In the event that the injection is not performed immediately after setting the dose, the display remains on until the injection is performed, after which the pen turns off after the inactivity described above.

As described below, the dosable quantity indicator can be used in administration devices that lack the automatic cartridge recognition system described herein, such as in devices in which different medications are being administered, each having only a single concentration. In such devices, the display at 582 may be a numerical value or other information representative of the actual dosable volume.

Referring now to FIG. 23, an exemplary embodiment of a drug injector apparatus is shown with an assembly for selectively rotating a drive sleeve of the present invention. The apparatus, generally designated 620, is shown in the form of a reusable injection pen, although other forms of portable injectors are within the scope of the invention.

Injection pen 620 includes a reusable pen base, generally designated 622, to which is attached a cartridge assembly generally designated 624 and further referenced in Figure 25. In Figure 23, the assembly The cartridge is shown substantially enclosed within a removable plug assembly 626. As further shown in Figure 27, the cap assembly 626 comprises a metal nose clip 627 crimped to the metal cap liner 629, and a plastic tubular cap insert 633 that is secured within the liner 629 and includes modules for its attachment to the cartridge holder. Insert 633 is not shown in Figure 24 for ease of illustration. The base of the pen 622 houses a dose setting and injection assembly that when actuated, causes an amount of the medication to be selected and then ejected from the cartridge assembly 624 through the needle assembly 628 of the pen to which referenced further in Figure 24.

With further reference to Figures 24-27, the cartridge assembly 624 is of a general type known in the art and includes a reusable cartridge holder or retention element 630. The proximal end 631 of the holder 630 may be connected in a suitable manner. , such as by internal threading, to the distal end of the pen base 622. The holder 630 defines a chamber into which a disposable cartridge 632 is loaded for use.

Cartridge 632 is of a conventional design generally described above and includes a drug-filled glass housing 634, piston 638, septum 644, and plug 646. A base piece 640 that is rotatably secured by a press fit All at once at the distal end of a drive screw 780 extendable from the base of boom 622 distributes moving force to piston 638. Openings or windows 642 on opposite sides of the cartridge holder 630 allow visual observation of the amount of medication remaining within the

ES 2 365 807 T3 cartridge contained. External threads 650 on the distal end of cartridge holder 630 allow mounting of shaft portion 652 of pen needle assembly 628. When assembly 628 is assembled as shown in Figure 24, proximal end 654 of needle cannula 656 contained in shaft portion 652 pierces septum 644, and medication is expelled from cartridge 632 through needle cannula 656 during injection use of pen 620. Although the needle assembly is shown as having a single injection needle, the needle assemblies that can be used with the 620 pen can be of various types of pen known in the art, including, but not limited to, assemblies with one or more needles. shortened injection tubes, including microneedle arrays.

In the embodiment shown, the pen needle assembly 628 further includes a needle cover 658 that has a tight fit to the shaft portion 652. The cap assembly 626 fits into the distal end of the cartridge assembly 624 when pen 620 is not in use, and is press fit so that it can be removed from the cartridge holder 630 using engaging catches and notches. A cam element in the cartridge holder 630 serves to align the plug assembly 626 so that it can rotate appropriately in the cartridge holder 630 when they are being connected to each other, and further pushes the plug assembly 626 axially away from the cartridge holder. cartridge 630 to disengage any snap fit between the two when the cap assembly is rotated relative to the cartridge holder during removal from the cartridge. A decorative offset ring 662 is securely connected, such as by adhesives, around the proximal end 631 of the cartridge holder 630 for aesthetic purposes.

In pen 620, once the contents of a given cartridge 632 are ejected through use of the injection device, a user disconnects holder 630 from the base of pen 622, removes and discards the spent cartridge 632, and then inserts a replacement disposable cartridge in the reusable holder which is then reconnected to the pen base 622 for use. Windows 642 assist in grasping the cartridge during removal of the cartridge from holder 630.

In an alternative embodiment not shown, and instead of the removable cartridge and holder shown, the cartridge assembly can be configured differently, as is known in the art, and as described above. For example, the cartridge assembly 624 can be assembled from the component parts during production into a disposable unit operated by a user as a single piece.

The cartridge holder 630 is removably mounted to the base of the pen 622 by threading its internally threaded proximal end into the external threading 664 of a tubular front housing 66. The front housing 666 is press fit by angularly spaced fasteners 667 to a distal end of a housing main body, generally designated 670. The angularly spaced keys 668 of the front casing 666 engage within keyways 671 of the casing main body 670 to prevent relative rotation between them.

The housing main body 670 is molded in one piece, but a multi-piece assembly can be employed. The housing end plug 676 is press fit by its protruding collar 677 to the proximal end of main body 670 to axially secure them together.

Extending proximally beyond and axially displaceable through the central opening of the end plug 676 is a cylindrical sleeve-shaped selector 680. A set of three notches or keyways 681 angularly spaced along the proximal edge of selector 680, and a set of three snap-fit ​​slot recesses 682 in the selector, respectively mate with keys 692 and ribs 693 of closing a base 690 of a selector assembly to provide a rigid and permanent assembly of the selector knob base 690 with the selector 680 through a one-time push fit. The dose knob assembly includes a cover 695 that is attached to the base 690 with adhesive, and with keys 696 on the cover 695 that engage the notches 694 in the base 690. In one embodiment, the base 690 of the knob the dose is plastic and the cover 695 is a die cut component. Grip elements 697 formed on the outer periphery of cover 695 enhance grip of the selector knob assembly during its rotation or selection to set the dose. Within its interior, selector knob cover 695 includes a centering boss, or alternatively a ring-shaped seat, that centers the distal end of priming spring 699.

Adjacent to its distal end, selector 680 includes a pair of radially projecting keys 683 that are inserted into longitudinally extending keyways (not shown) formed on the inner surface of barrel 700. This keyway provides consistent rotational movement. between selector 680 and barrel 700, while allowing selector 680 to move axially relative to barrel 700. A double-beginning helical thread 685 protruding into the cylindrical inner surface of selector 680 engages or threads into helical grooves 712 formed in the outer surface of a drive sleeve 710 of a drive sleeve assembly, generally designated 708 . By making one of the dual-start threads 685 and its corresponding groove 712 thinner than the other thread and groove, a one-way assembly of the selector on the drive sleeve is achieved. In alternative embodiments, different thread configurations may be used, including a single groove and thread connection. An arrowhead 686 formed on selector 680 shows that

ES 2 365 807 T3 the direction selector 680 is inserted into the drive sleeve 710 to facilitate assembly. Zero stop 713 is the distal end of grooves 712 that is abutted by threading of selector 685 to prevent selector 680 from setting a selection below the pen zero setting. A maximum dose stop, consisting of a collar 720 with a pair of axially extending locking prongs 721 that snap into recesses 714 in drive sleeve 710, fits around the proximal end of drive sleeve 710 to connect the drive sleeve 710. Threading of selector 685 to the proximal end of slots 712 to prevent selector 680 from setting a selection above the maximum setting.

The barrel 700 is formed with an annular rib 702 at its proximal end that extends continuously around the outer circumference of the barrel. The distal face of the barrel rib 702 includes a series of axially extending unidirectional teeth 703 for engaging a device that upon actuation clicks 725 of the ring selector. The proximal face of the device that upon actuation emits a selector click 725 includes a ring of axially extending unidirectional teeth 726 that engage the barrel teeth 703. The distal face of the device that upon actuation emits a selector click 725 includes a ring of axially extending unidirectional teeth 728, which mesh with axially extending unidirectional teeth 732, on the proximal face of a selector clutch 730 cancel.

A set of four keys 733 protrudes radially outward from the outer periphery of clutch 730 and slidably engages within axially extending keyways 673 in casing main body 670 to prevent rotation of clutch 730 relative to casing. . A helical compression spring 735 having one end abutting a sealing piece 672 formed in the housing main body 670 and the other end seated on the distal face of selector clutch 730 urges clutch 730 into the device that when actuated it clicks 725 on the barrel rib 702 to provide audible clicks during dose selection and to provide targeting positioning during dose selection. In particular, when the dose selection of the selector 680 is increased so that it moves proximally axially, the teeth 728 of the device that when actuated clicks slide past the teeth 732 of the clutch, so that the gear of the teeth 726 of the device that when actuated emits a click with the teeth 703 of the rotating barrel 700 produces the rotation of the device that when actuated emits a click 725. When the selection of the dose of the selector 680 is decreased, the teeth of the barrel 703 slide past the teeth 726 of the device that when actuated emits a click when the device that when actuated emits a click 725 is fixed in rotation by the gear of the teeth 728 of the device that when actuated clicks with the teeth 732 of the clutch 730 fixed in rotation. As is known in the art, this sliding movement of the teeth produces the clicks of the selector.

Barrel spring 735 biases barrel 700 proximally such that, except during injection actuation of pen 620 as described below, the axially extending external splines 704 at the distal end of the barrel do not engage. with the complementary internal grooves of the sealing piece 718 formed in the main body 670 of the housing. The grooves of the seal 718 are twenty-four in number and are angularly equidistant from the circumferential around the driver sleeve. Proximal retraction of barrel 700 is stopped when the proximal face of barrel rim 705 abuts the flange of driver sleeve 716 and driver sleeve has been retracted proximally until ring 760 has depressed the device which when actuated clicks 754 in full engagement with the grooves of the housing seal 718. The grooves 704 are integrally formed on the inward rim 705 of the barrel into four arcuate segments, the spacing between the segments providing space for the tabs 655. The proximal face of rim 705 also serves as a contact face for force. of injection that is placed on the driving sleeve 710, as well as a bearing surface for the relative rotational movement of the driving sleeve 710 and the barrel 700.

As the barrel 700 is distally displaced to compress the barrel spring 735 during injection, the grooves of the barrel 704 engage with the internal grooves of the plug 718 to prevent rotation of the barrel 700 relative to the housing 670. In In an alternative embodiment, it may be possible to prevent rotation of the barrel 700 relative to the housing 670 with interconnected, unidirectional teeth.

The distal region of drive sleeve 710 is generally cylindrical, although it is shown slightly faceted to improve manufacturability, and includes circumferential groove 748, diametrically opposed recesses 750, and diametrically opposed grooves 746. The injection device that clicks when actuated 754 is rotatably fixed to the drive sleeve 710 by four tabs 655 spaced 90 ° apart formed in one piece with the drive sleeve that engage in four corresponding recesses 647 in the proximal face of the device that when actuated it clicks 754. The actuated device 754 is pushed in the proximal direction by the clutch spring 758. The retaining ring 760 fits into the groove 748 and prevents disassembly of the device which, when actuated, emits a click of the drive sleeve. When the driver sleeve 710 is urged proximally by actuation of the barrel spring 735, the tabs 655 engage the grooves in the seal 718 and prevent rotation of the driver sleeve 710. When the spring thrust of the barrel 735 is overcome and the driver sleeve moves distally during injection, the tabs 655 move away from the seal 718 to allow the tabs 655 to disengage from the grooves of the seal 718. , thus allowing the drive sleeve to

IS 2 365 807 T3

710 rotate. The clicking device 654 is allowed to move axially relative to the drive sleeve, allowing the teeth of the clicking device 656 to slide over the inclined end faces of the part grooves. seal 718 when the drive sleeve 710 is rotated to create an audible click indication of the drive and to provide rotational positioning during injection. The distal end of clutch spring 758 abuts the proximal face of an injection clutch 762 that is rotatably attached to drive sleeve 700 by keys 764 that slide within slots 746. Clutch 762 is further press fit into gaps 750 so that it has limited axial play in drive sleeve 710 to accommodate axial movement of drive sleeve during injection, and axial displacement of floating nut 776 during injection. installation of cartridge assembly 624. The distal face of clutch 762 includes a ring of teeth 766 that transmit torque.

The teeth of the clutch 766 selectively mesh with the teeth 772 of a drive clutch 770 axially retained within the injection nut 776. The internal keys 774 of the clutch 770 slide within two longitudinal keyways or slots in the threaded drive screw 780 and they cause the drive screw to rotate with the clutch. The keyways or slots in the drive screw are formed by triangular shaped straight cuts or corners in the screw along its length, which cuts are generally on opposite sides of the screw. The leading edge of the first corner cut is radially aligned on the screw, as well as diametrically aligned with the leading edge of the second corner cut, resulting in the trailing or misaligned edges of the first and second corner cuts being parallel . Drive screw 780, which extends into an axial hole through drive sleeve 710, is threadedly engaged with an internally threaded hole within injection nut 776. Nut 776 is rotatably fixed but can be moved axially within casing 670 by angularly spaced keys 777 that slide into axially aligned recesses 674 in casing main body 770. When the drive screw 780 is rotated by forced rotation of the drive clutch 770, the drive screw advances in the distal direction as it threads through the nut 776. Priming spring 699 snaps into the proximal end of drive screw 780. During cartridge replacement, when screw 780 is retracted when rearming during assembly of a cartridge assembly 624 filled with replacement cartridge At the base of pen 622, spring 699 is compressed into contact with selector knob cover 695 to push drive screw forward toward cartridge piston 638. The injection nut 776 is biased in the distal direction by an injection spring 784 that acts between a housing seal and the proximal face of the nut 776, which thrust is overcome by engagement with the distal end of the cartridge 632 during the cartridge assembly assembly 624.

In the embodiment shown, electronic components are used to determine and display the dose that has been set and remains to be injected during subsequent use of the pen 620. Therefore, in the embodiment shown, the selector 680 need not be provided with numbers or other markings that provide a user with a visual indication as to what amount of medication the pen has been tampered with for injection during use and Therefore, the selector serves as an extension of the knob that can be grasped. Electronic components include an electrically conductive matrix pattern 800 around a plastic sleeve 802 that is attached, through a method such as adhesive bonding, press fit, or force fit, to drive sleeve 710. An axially extending sleeve key 802, not shown, fits into an opening in annular flange 716 of drive sleeve 710 to prevent relative rotation, and allows proper orientation of die 800 relative to drive sleeve 710. The flange 716 also provides a bearing surface for relative movement between the drive sleeve 710 and the barrel 700, carries the distal axial load of the injection, and carries the proximal axial retraction load via the spring 735. The sleeve including the matrix 802, together with drive sleeve 710 form the drive sleeve assembly 708 that rotates and moves as a single unit during operation.

Die sleeve 802 is electrically contacted by contact ends of a pair of insert molded leaf spring contact assemblies, generally designated 805 and 806, further shown in Figure 29. Contact assembly 805 includes a plastic base 807 that inserts into the cross portion of a T-shaped opening 808 in barrel 700. A wedge-shaped periphery of base 807 prevents excessive insertion. Four leaf springs 810, 811, 812, and 813 are captured in base 807. Matrix contact ends 810a, 811a, 812a, and 813a of leaf springs 810-813 extend through the base of the opening 808 and rub against the die sleeve to make electrical contacts with the conductive pattern 800. Cable contact ends 810b, 811b, 812b, and 813b of leaf springs 810-813 extend external to barrel 700 and fit within the four most proximal circumferential grooves 706 of a set of six such grooves on the exterior of the barrel. barrel 700 housing contact rings.

Contact assembly 806 is constructed similarly to contact assembly 805 with a plastic base 814 that contains three metal leaf springs 816, 817, and 818 that include die contact ends 816a, 817a, and 818a and die ends. 816b, 817b and 818b wire contact. The plastic base 814 is inserted into a barrel opening not shown that is offset longitudinally and angularly from the barrel opening 808. Wire contact ends 816b, 817b, and 818b extend external to barrel 700 and engage

ES 2 365 807 T3 within the three most distal circumferential grooves 706 of the set of six of said grooves. By placing contacts 813 and 816 in the same longitudinal position and in the same slot 706, a redundant contact is provided for grounding the matrix pattern. In the embodiment shown, die contact ends 816a, 817a, and 818a are angularly offset 180 degrees from die contact ends 810a, 811a, 812a, and 813a, but other spacings may be employed.

Referring again to Figure 27, surrounding the barrel 700 are six contact rings made of metal sheaths or coil springs 820-825. Rings 820-825 sit within six axially spaced circumferential grooves 706 on the outside of barrel 700, as well as grooves 809 formed in base 807 and grooves 815 in base 814, and are in electrical contact with the wire contact ends 810b, 811b, 812b, 813b and 816b, 817b and 818b, respectively. Rings 820-825 allow the contacts of a stationary rotating slide assembly 838 to remain in contact with the rings, regardless of the relative rotational positions of the rings.

The matrix 800 is designed and constructed conceptually similar to the matrix 500, but is adapted to work with the angular positions of the contact ends 810a, 811a, 812a, 813a, 816a, 817a, and 818a of the matrix, such that Twenty-four different angular orientations of the barrel 700 with respect to the power pack 710 can be recognized. A suitable matrix 800 is shown in two dimensions in FIG. 30. The rounded protrusions shown in the die in Figure 30 are not part of the effective pattern, but rather are used to help hold the pattern in the part where it is insert molded. Furthermore, the pattern of the matrix 800 is designed so that single point errors in the contacts related to the matrix data associated with the 810a, 811a, 812a, 817a, and 818a contact ends, and not the 813a ends and 816a from contact to ground, which are different from the expected change when moving from one die position to an adjacent die position in each direction, they are easily detected by the 867 controller in order to detect pen operation errors every time the pen is powered on. Specifically, the matrix 800 is designed so that during the relative rotational movement of the pen components that the matrix moves one position from its current position (for example, a 15 ° movement for the twenty-four column matrix shown), changing one of the signals associated with the matrix contact ends other than contacts 813a and 816a, results in only one of the following: (a) a change to the code corresponding to an adjacent position, (b) a change to a code corresponding to none of the twenty-four positions, or (c) a change to a code corresponding to a position outside of a given range, such as a range from two to six positions, inclusive, away from the current position. Alternatively, other ranges may be employed, from two to three or four or five positions, or from two to eight or more positions. In other words, for any of the twenty-four rotation positions, the array data code within the range of two to six positions away from a given position in any direction differs by at least two data points from the given position. Therefore, during the use of the pen, either during manual movement of the selector to increase a dose, or during manual movement of the selector to decrease a dose, or during the injection of the medication, if the controller receives information that suggests a movement of more than six turning positions from the previously recognized position, in which the pen considers the movement to be too great a movement and therefore an error, Unless within a short period of time set by the manufacturer, such as the time between screen updates, during which time the controller continues to check the matrix data, the received information returns within the accepted range of positions. from the previously recognized position, the controller produces an error message to display. If the received information returns to the accepted range within the set period, the pen controller recognizes the erroneous reading as an aberration and ignores it as such, and does not display an error message or require a pen reset.

It will be recognized that one of ordinary skill in the art, in light of the teachings herein, can provide other ways for the controller 867 to determine the validity of a detected location code, based on a previously recognized location code. For example, the matrix 800 need not provide unique patterns for all twenty-four positions of a revolution, but only for those positions within a valid range, such as one to six positions, on either side of a given position. The controller would compare a detected position code with the position codes within the range adjacent to the previous code to determine around which non-unique position codes it was being detected. The above approach would allow all twenty-four positions to be captured via a five-row matrix, which is a four-bit signal, instead of the six-row matrix 800 shown, which is a five-bit signal. Reduction to a five row die is not required, but could be used to reduce the number of parts or to decrease the length of the device. If a five-bit signal is still used this can improve the overall reliability of the device without increasing the length of the device, since redundancy can be added.

Furthermore, a matrix 800 could be created in which the matrix data associated with the two contact ends of the matrix other than the contact ends 813a and 816a changes when a column of the matrix 800 is changed, rather than just a data point, as described directly above. Such an approach would allow the 867 controller to reject all single point errors from said sensor contacts, rather than just those that could result in a change of more than one data point, thereby improving the reliability of the device. For such a two-bit shift, if twenty-four unique rotation positions are desired, a

ES 2 365 807 T3 seven-row matrix pattern, as opposed to the six-row pattern shown.

Each of the 820-825 contact rings is directly engaged by one of six 840-845 slide contacts of a slide guide assembly, generally designated 838, further shown in Figure 28. The 840-845 slide contacts they are made of metal in a leaf spring shape and are mounted on a plastic chassis 847 between a pair of keys 849 projecting radially from the chassis. Keys 849 are inserted into a pair of circumferential grooves or keyways 707 in barrel 700 that flank the set of six grooves 706 on each axial side. Engagement of keys 849 within slots 707 causes slide assembly 838 to move axially with barrel 700, but allows barrel 700 to rotate relative to slide assembly 838, all the time with contacts. 840-845 slide in electrical communication with contact rings 820-825.

The slide assembly 838 is fixedly connected to a flexible circuit board 865 so that the contacts can transmit the detected matrix pattern through the circuit board 865 to the microcontroller. The slide assembly 838 is positioned on the plate during manufacture through a pair of cylinders projecting from the rear of the chassis 847 and fits within notches 851 in the plate. The chassis 847 of the slide assembly fits into an opening 678 of the main body 670 of the housing, which opening serves as a keyway in which the slide assembly 838 can move axially but is fixed in rotation with respect to to the casing.

To obtain detection of the relative movement of the barrel 700 and the drive sleeve assembly 708, the matrix 800 in the sleeve 802 provides a selective conductive path between the six contact rings 820-825. Contact ring 823 is always grounded, and that grounded ring, through its associated matrix contact ends 813a and 816a, is always in contact with and thereby grounds matrix 800, except in the exit rotation position when none of the other rings 820, 821, 822, 824, and 825 through their associated die contact ends are in contact with die pattern 800. The matrix pattern 800 selectively cuts current through the appropriate rings to form a code which is then picked up by slide guide contacts 840-845 and sent to the microcontroller for recognition.

Although the array was previously described as grounded, in other embodiments, the array could be triggered not by a ground signal, but instead by whatever voltage is perfectly recognizable to the controller. For example, for a controller where the only options are logic high and ground signal, instead of the ground signal described above, as the trigger signal, a logic high signal of approximately three volts can be used. to activate the matrix.

The slide assembly 838 also includes an injection switch, generally designated 853. The switch 853 has a resilient contact 855 comprised of leaf spring metal with a sloped region 857. When the barrel 700, and therefore the slide assembly 838, are moved axially a short distance during a first phase of the injection operation, the inclined region 857 is pressed radially outward by contact with the surface of the housing. 679 so that spring contact 855 completes a circuit with fixed contact 861 of the injection switch. Spring contact 855 includes a contact end 859, and fixed contact 861 includes a contact end 863, which are each electrically connected to circuit board 865 to convey electrical signals to the microcontroller. During this axial movement of the slide assembly, the portion of the flexible circuit board 865 on which the slide assembly is mounted also moves axially relative to the rest of the plate. The closure of the injection switch 853 is recognized by the microcontroller 867 as the start of the pen injection operation, rather than a decrease or increase of the pen dose being selected in preparation for injection.

Flexible circuit board 865 is a two-layer flexible circuit board that wraps around the housing main body 670 and is connected to a main body 670 with positioning pins and adhesive. The flexible 865 circuit board serves as the base on which the 867 microcontroller is mounted, which is programmed to control the electronic operations of the 620 pen, 869 batteries to supply power to the electronic components, and an 871 LCD screen.

The electronic components of the pen 620 are capable of sensing the relative rotational movement of the driver sleeve assembly 708 within the barrel 700, barrel, and driver sleeve assembly that are held in a consistent axial position with respect to each other. During dose setting, barrel 700 rotates while driver sleeve assembly 708 is fixed in rotation within the housing, and during dose injection, barrel is fixed in rotation and driver sleeve assembly rotates within. from the casing.

A clear plastic lens 873 is adhered to the main body 670 of the housing, and it protectively covers the screen 871 and provides increased screen reading. Pushbutton 875 used to control pen electronics is pivotally mounted on lens 873 and is connected to a switch actuator 874 that activates a domed quick disconnect switch.

ES 2 365 807 T3 which is electrically connected to circuit board 865. Microcontroller 867 is programmed to turn on the display for operation when button 875 is manually pressed. In one embodiment, button 875 may be used to change the settings. data stored in memory, or a setting of a clock associated with the microprocessor. For example, data stored in memory associated with the microprocessor, such as the date, can be set by first pressing and holding button 875 for a set period, such as three seconds, to cycle the pen to a setting mode, and then axially pressing on the selector knob assembly to move the slide assembly 838 and activate the injection switch 853 to increase the data being changed. A bezel 877 adhered to the main body 670 of the housing serves as a decorative edging piece and together with the lens 873 and push button 875 is exposed through a window 879 of an outer skin 880 formed of metal and adhering to the main body 670 of the casing.

A foam gasket 882 is trapped between the underside of lens 873 and an upper surface of flexible circuit board 865. The seal 882 prevents any fluid that is present on the exterior of the pen along the interconnection of push button 875 and lens 873 from reaching the internal electronics of the pen 620. An 885 structural filler, which is provided to facilitate boom assembly and fits within notches in the housing main body 670, serves as an additional base on which the 871 shield adheres, and is an additional attachment surface. for coating 880.

A cover portion 887 is adhered to the main body 670 of the housing, and has an internal relief to allow space for electronic components. A metallic outer skin 880 is adhesively mounted to both the housing main body 670 and the cover portion 887 to provide an attractive appearance to the pen 620.

The structure of the injection pen 620 will be further understood in view of the following explanation of its operation. When the user needs to inject a dose of medication, the pen 620 is first turned on by pressing button 875, which causes the display 871 to present the current date and time according to the pen's internal clock, and a "0" as to the amount of medicine that the pen is ready to deliver. Pen 620 can also be turned on by beginning to rotate the selector knob assembly, or alternatively, by depressing the selector knob assembly to activate the injection switch. If after turning the pen on via button 875 or by pressing the selector knob assembly, the selector knob assembly is pushed axially distally so that the injection switch 853 is activated, causing the display to show the date , time and amount of the last injection. If the memory of the 620 pen is adapted for memory of multiple doses, each additional distal plunger push of the selector knob assembly will then cause the previous date, time and quantity to be displayed on the screen so that the user can cycle through the previous stored doses, which can be ten or more doses. To exit the dose memory mode, the user can wait for a set period of time, such as eight seconds, without selecting a dose with the dose knob or pressing any button, or by selecting a dose with the dose knob from the position “0”, or by pressing and releasing the dose knob a sufficient number of times to cycle through the entire multiple dose memory.

Pen 620 is then manipulated so that the user selects the dose to be administered. The following explanation will assume that the pen 620 has already been primed as suggested, which priming step involves merely operating the pen in the manner described above to discharge a small dose to expel any amount of air from the cartridge. In a pen having multiple dose memory, an indication that said dose was a priming dose can be marked in memory, such as by pressing and releasing button 875 immediately after priming delivery whenever the microprocessor 867 detects that the switch Injection 853 is no longer activated, such as before the expiration of a timer after the five second injection. When a user reviews the doses in memory, a priming dose can be indicated by that alternating dose over time with a "P" on the display. Alternatively, the prime mark may involve pressing and releasing the mode button 875 by the user after reaching a prime dose when reviewing the doses stored in the dose memory.

To select the dose, the user grasps the cover of the selector knob assembly 695 typically between the thumb and forefinger and begins to rotate it relative to the rest of the pen base 622. This rotation produces the corresponding rotation of the selector 680 , and furthermore the barrel 700 rotates simultaneously due to its keying with the selector. As selector 680 and selector knob assembly rotate, they also translate axially in the proximal direction as selector 680 threads into drive sleeve 710 due to its threaded engagement therewith. As the selector is unscrewed, it extends proximally well beyond the housing of the boom base, and the selector drive assembly travels proximally and further from the housing. The drive sleeve 710 is fixedly held in rotation by engagement of tabs 655 within the grooves of the housing. If the user rotates beyond a desired dose, the rate knob assembly and selector 680, and therefore barrel 700, can be turned in the opposite direction, an operation that rotates selector 680 back down the cuff. drive 710. During this movement of the selector to decrease the dose, the drive sleeve is held in a fixed manner in rotation due to its resistance to rotation attributable to the tabs 655. During the rotation of the barrel 700, which is stationary

ES 2 365 807 T3 axially relative to the drive sleeve, the display 871 displays a continuously changing value of the amount of medication that the pen 620 would inject if actuated via plunger thrust at any given point during that rotation. In particular, the display 871 is controlled by the microprocessor 867, which recognizes the rotational position of the barrel 700 with respect to the drive sleeve 710 based on input from the mechanisms of the matrix pattern 802, rings 820-825, slide guide assembly 838 and circuit board 865. The user stops the rotation of the selector when he observes that the display 871 indicates the amount of medication to be injected. At this point, the injection pen 620 is configured as shown in the cross-sectional view of Figure 25, since the cap assembly and cover 658 have been previously removed during the priming step as usual.

The user is now ready to inject the set dose, an injection operation that is carried out in two phases. Initially, and in the first phase, the pen is mechanically moved from a dosing mode to an injection mode by moving the dose knob and selector proximally a small distance, such as 0.080 inches (2.032 mm) of travel back to the inside of the pen housing. In particular, the user, typically with his thumb, applies a plunger biasing force on the proximal face of selector knob cover 695. This plunger push places an axial load on selector threads 685, which load, through drive sleeve thread 712, advances drive sleeve assembly 708 distally within boom 620 and without rotation of selector 680 relative to the shaft. drive sleeve assembly due to friction forces. This movement of the drive sleeve moves the barrel 700 distally or forward due to direct contact of the distal face of the flange 716 with the rim of the barrel 705. The distal movement of selector 680, drive sleeve 710, and barrel 700 stops when barrel 700 reaches a location where splines 704 mesh with splines in the housing seal, at which point the barrel it is fixed in rotation, and the selector, which is keyed in rotation to the barrel, is also fixed in rotation.

When pen 620 has reached this state, shown in Figure 26, the second phase of the injection operation begins, as any additional plunger pushing force applied to the selector knob moves the selector knob assembly and selector 680 distally and without rotation, translation that causes rotation of drive sleeve 710. As the drive sleeve 710 is rotated, the injection clutch 762 is also rotated, forcing the rotation of the injection screw 780, which due to its engagement with the injection nut, advances the screw into the cartridge to push the medicine out of the needle. As the drive sleeve 710 rotates, the click injection device 754 bounces in and out of the housing grooves to produce an injection click. Selector 680 is plunger-pushed until it reaches a plunger-pushed axial position corresponding to the position shown in Figure 24, position in which position selector thread 685 abuts zero stop 713 and sleeve rotation stops. drive 708. During this second phase, if the injection nut 776 has been pulled all the way back, the injection nut spring 784 ends the injection by moving the nut 776 distally when the plunger push of the selector is complete.

During both phases of the injection operation, the microcontroller 867 continuously receives input from electronic sensors that capture the relative rotational movement of the barrel 700 and the driver sleeve assembly 708. The display 871, throughout the injection process, displays the quantity to be injected still in real time, subject to the limitations of electronic components, allowing the display to be updated only, for example, eight times per second. Since the injection switch 853 is activated when the barrel is moved distally, the microprocessor uses the input of the switch 853 to distinguish between the selection of a dose and the injection. The signal from the switch can also be used by the microprocessor to cause the time, date and amount being injected to be stored in memory for later reference.

After the injection pen 620 is used to inject the set dose, the controller 867 automatically returns to an off state, and the display elements of the display 871 are all turned off, after a specified period of time of inactivity. In the event that an injection is not performed immediately after setting a dose, the display remains on until the injection is performed, after which the pen is disconnected after the inactivity described above. Since the full plunger push process of the Dose Set Knob Assembly and Selector 680 during pen use automatically resets them, setting the dose the next time Pen 620 is used requires simply turning the set. selector control and selector 680 from its position pushed by plunger and without additional manipulation.

Microcontroller 867 can use input received from injection switch 853 and electronic sensors that sense the relative rotary movement of the barrel and driver sleeve assembly to diagnose whether the injection pen is operating properly. For example, the pen can be programmed to fail if the microcontroller detects that injection switch 853 is on while electronic sensors are indicating that a dose increase is being selected. In addition, an error message can also be communicated to the user through the display if the microcontroller detects that the injection switch 853 has not been activated, even though the input from the electronic sensors suggests that the detection of the selector is of doubtful precision, such as produced by the selector which has been manually turned too fast by the user.

IS 2 365 807 T3

Although a particular mechanism for converting the rotation of the drive sleeve to an axial movement of the cartridge plunger is described in Figures 23-27, this can be replaced by other less complicated mechanisms known in the art, such as one in which the drive sleeve it is screwed directly into a driver screw, within the scope of the present invention.